What's behind the India-China border stand-off?

For four weeks, India and China have been involved in a stand-off along part of their 3,500km (2,174-mile) shared border.

The two nations fought a war over the border in 1962 and disputes remain unresolved in several areas, causing tensions to rise from time to time.

Since this confrontation began last month, each side has reinforced its troops and called on the other to back down.

How did the row begin?

It erupted when India opposed China's attempt to extend a border road through a plateau known as Doklam in India and Donglang in China.

The plateau, which lies at a junction between China, the north-eastern Indian state of Sikkim and Bhutan, is currently disputed between Beijing and Thimphu. India supports Bhutan's claim over it.

India is concerned that if the road is completed, it will give China greater access to India's strategically vulnerable "chicken's neck", a 20km (12-mile) wide corridor that links the seven north-eastern states to the Indian mainland.

Indian military officials told regional analyst Subir Bhaumik that they protested and stopped the road-building group, which led Chinese troops to rush Indian positions and smash two bunkers at the nearby Lalten outpost.

"We did not open fire, our boys just created a human wall and stopped the Chinese from any further incursion," a brigadier said on condition of anonymity because he was not authorised to speak to the press.

Chinese officials say that in opposing the road construction, Indian border guards obstructed "normal activities" on the Chinese side, and called on India to immediately withdraw.

What is the situation now?

Both India and China have rushed more troops to the border region, and media reports say the two sides are in an "eyeball to eyeball" stand-off.

China also retaliated by stopping 57 Indian pilgrims who were on their way to the Manas Sarovar Lake in Tibet via the Nathu La pass in Sikkim. The lake is a holy Hindu site and there is a formal agreement between the neighbours to allow devotees to visit.

Bhutan, meanwhile, has asked China to stop building the road, saying it is in violation of an agreement between the two countries.

What does India say?

Indian military experts say Sikkim is the only area through which India could make an offensive response to a Chinese incursion, and the only stretch of the Himalayan frontier where Indian troops have a terrain and tactical advantage.

They have higher ground, and the Chinese positions there are squeezed between India and Bhutan.

"The Chinese know this and so they are always trying to undo our advantage there," retired Maj-Gen Gaganjit Singh, who commanded troops on the border, told the BBC.

Last week, the foreign ministry said that the construction "would represent a significant change of status quo with serious security implications for India".

Indian Defence Minister Arun Jaitley also warned that the India of 2017 was not the India of 1962, and the country was well within its rights to defend its territorial integrity.

What does China say?

China has reiterated its sovereignty over the area, saying that the road is in its territory and accusing Indian troops of "trespassing".

It said India would do well to remember its defeat in the 1962 war, warning Delhi that China was also more powerful than it was then.

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On Monday, a Chinese foreign ministry spokesman said that the border in Sikkim had been settled in an 1890 agreement with the British, and that India's violation of this was "very serious".

The Global Times newspaper, meanwhile, accused India of undermining Bhutan's sovereignty by interfering in the road project, although Bhutan has since asked China to stop construction.

What's Bhutan's role in this?

Bhutan's Ambassador to Delhi Vetsop Namgyel says China's road construction is "in violation of an agreement between the two countries".

Bhutan and China do not have formal relations but maintain contact through their missions in Delhi.

Security analyst Jaideep Saikia told the BBC that Beijing had for a while now been trying to deal directly with Thimphu, which is Delhi's closest ally in South Asia.

"By raising the issue of Bhutan's sovereignty, they are trying to force Thimphu to turn to Beijing the way Nepal has," he said.

What next?

The region saw clashes between China and India in 1967, and tensions still flare occasionally. Commentators say the latest development appears to be one of the most serious escalations in recent years.

The fact that Tibet's spiritual leader, the Dalai Lama resides in India has also been a sticking point between the two countries.

This stand-off in fact, comes within weeks of China's furious protests against the Dalai Lama's visit to Arunachal Pradesh, an Indian state that China claims and describes as its own.

Relations between the Asian giants, however, may not slide further as China has allowed 56 Hindu pilgrims, who entered through the Indian state of Himachal Pradesh, to visit the Manas Sarovar site.

"They are heading for the lake and they are safe," senior tourism official Dheeraj Garbiyal said last week.

This, experts say, shows that the Chinese are not raising tensions on the whole border but specifically on the Sikkim-Bhutan stretch.

BBC NEWS

Chinese deities flown on business class to Malaysia

Images of three revered Chinese deity statues went viral on social media after they were seen travelling in business class on a flight from China's port city of Xiamen to the Malaysian capital Kuala Lumpur. But what is the story behind it?

Who are the divine passengers?

The first was the Chinese sea goddess Mazu (also known as Matsu), widely worshipped in southern China as well as countries with large Taoist and Chinese Buddhist communities such as Malaysia, Vietnam and Taiwan.

She is a patroness of the sea and is believed to protect fishermen and sailors.

The other two statues are Qianliyan and Shunfeng'er, heavenly guardians of the goddess.

Qianliyan is known for his powers of far-sightedness while the demon Shunfeng'er possesses the incredible ability to hear all sounds carried by the wind, a role believed to aid sailors and passing ships from advancing storms.

Why were they in business class?

The three statues were sent to Malaysia and Singapore as part of an inaugural cultural exchange tour to pay tribute to the sea goddess and celebrate a festival in her name. It was organised by the Meizhou Mazu Ancestor Temple in China.

Photos being widely circulated on Chinese social media showed the statues leaving their coastal temple home and "checking in" at Xiamen Gaoqi International Airport.

"How did she get through security checks?" asked amused user Tong Huichun on the popular WeChat messaging app.

"It's normal for Mazu to give a tour. It's too far away so she's taking a flight. Taking a boat will take too long," said another WeChat user Gong Chang.

Temple staff told BBC News that the religious statues were escorted by "a delegation of more than 130 people" and brought onto a Xiamen Airlines flight heading to Kuala Lumpur International Airport.

They flew in comfort in business class, on tickets costing 2,091 yuan (£237) each.

With assistance from airline staff, devotees fastened the sacred statues into first row seats and "widened" them to allow more space.

Taking turbulence into consideration, the statues' feet were firmly fixed onto the seats with special harnesses.

"This is basic respect we have for the culture of Goddess Mazu," said a spokesperson who received the statues in Malaysia. "They were also more than 6ft high, so they had to fly business class."

They even had special passports, which staff from the temple said were a "special courtesy" provided by the airline.

Journey to the South: Where were they travelling from?

The statues came from a sacred sea temple located off the shores of Fujian province, known to its worshippers as being the birthplace of goddess Mazu.

They travelled more than 2,800km to another temple, the Thean Hou Chinese 

Temple staff highlighted the importance of their voyage.

"This is the body of our divine goddess, a symbol of Chinese folk culture," a representative told BBC News, adding that processions were held to celebrate the statues' safe arrivals.

All three statues have made their way to neighbouring Malacca city and are on their way to Singapore. They will then return to their home in China.

BBC NEWS

Thirteen rescued as Marbella 'prostitution ring' smashed

Thirteen women forced to work as prostitutes in the Spanish resort near Marbella have been freed, police say.

The victims are thought to have been brought from Bulgaria to the Costa del Sol, where they were made to work on the streets of Puerto Banus.

Police also arrested 34 suspected gang members across Europe.

In a statement, police said the Bulgarian gang had sought "total control" of the upmarket resort.

They had brought women from poor areas of Bulgaria and forced them to work as prostitutes, threatening them and their families with violence if they refused.

The women were also made to steal from their clients, some of whom may have been drugged, police said.

The arrests came almost three years after police were made aware of the prostitution ring by a woman who escaped the gang's clutches.

It was then, they said, they had discovered "an enormous international network that operated mainly in Spain and Bulgaria".

Spanish police - who worked with their Bulgarian counterparts and the European Union police agency Europol - said most of the arrests were made in Spain, with eight in Bulgaria.

They also carried out searches at properties in both countries.

BBC NEWS

Emmanuel Macron aboard France's nuclear submarine

President Emmanuel Macron has spent several hours underwater aboard a nuclear submarine to signal commitment to France's nuclear deterrent.

During the visit to "Le Terrible" submarine off Brittany coast, Mr Macron reportedly took part in a simulated missile launch.

France will be the sole EU nation with nuclear arms after 2019, when the UK is expected to leave the 28-member bloc.

Meanwhile, the new French government easily won its first confidence vote.

The cabinet led by Prime Minister Edouard Philippe was backed by 370 MPs in the lower house, with only 67 voting against.

Mr Philippe set out proposals for public spending cuts and labour reforms - a move condemned by the trade unions, who have threatened protest strikes in the autumn.

Macron's meteoric rise

What's next on president's agenda?

On Tuesday, President Macron was taken by helicopter to "Le Terrible" submarine in the Atlantic, about 300km (186 miles) off France's coast.

Mr Macron's office later published a photo, showing the president being lowered down aboard the submersible.

Mr Macron stressed the importance of France's nuclear deterrence, describing it as the "keystone of security".

The reported missile launch simulation was part of the president's daylong visit to nuclear weapons facilities at the Ile Longue base, near Brest.

It is home to the country's four nuclear-powered, ballistic missile-carrying submarines.

France maintains a fleet of nuclear-armed submarines and strike planes, and has about 300 operational nuclear warheads.

Support for the deterrent is deeply rooted in French society and history, ever since it became a nuclear power in the 1960s, correspondents say.

BBC NEWS

The US has confirmed that North Korea on Tuesday tested an intercontinental ballistic missile (ICBM).

Secretary of State Rex Tillerson called it a "new escalation of the threat" to the US and the world and warned that Washington "will never accept a nuclear-armed North Korea".

Pyongyang earlier said it was its first successful intercontinental ballistic missile test.

US officials believe the North may now be able to fire a missile to Alaska.

However, experts say it cannot accurately hit a target.

In response to the test over the Sea of Japan, the US and South Korea conducted a "combined [military] exercise to show our precision fire capability", Pentagon spokeswoman Dana White said in a statement.

The US also asked for an urgent meeting of the UN Security Council to discuss the issue. A closed-door session of the 15-member body is expected later on Wednesday.

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In a statement, Mr Tillerson said: "The United States strongly condemns North Korea's launch of an intercontinental ballistic missile.

"Testing an ICBM represents a new escalation of the threat to the United States, our allies and partners, the region, and the world."

Mr Tillerson stressed that "global action is required to stop a global threat".

And he warned that any nation that provided economic or military benefits to the North or failed to fully implement UN Security Council resolution was "aiding and abetting a dangerous regime.

What did North Korea say earlier on Tuesday?

The announcement on North Korea state television said the Hwasong-14 intercontinental ballistic missile (ICBM) test was overseen by leader Kim Jong-un.

It said the projectile had reached an altitude of 2,802km (1,731 miles) and flew 933km for 39 minutes before hitting a target in the sea.

North Korea, it said, was now "a full-fledged nuclear power that has been possessed of the most powerful inter-continental ballistic rocket capable of hitting any part of the world".

North Korea's official KCNA news agency later quoted Kim Jong-un as saying the test was a "gift" to the Americans on their independence day.

The launch, the latest in a series of tests, was in defiance of a ban by the UN Security Council.

But experts also believe that Pyongyang does not have the capacity to miniaturise a nuclear warhead that can fit onto such a missile.

How advanced is North Korea's nuclear programme?

How far could this missile travel?

The big question is what range it has, says the BBC's Steven Evans in Seoul. Could it hit the United States?

David Wright, a physicist with the US-based Union of Concerned Scientists, says that if the reports are correct, this missile could "reach a maximum range of roughly 6,700km on a standard trajectory".

That range would allow it to reach Alaska, but not the large islands of Hawaii or the other 48 US states, he says.

It is not just a missile that North Korea would need, our correspondent adds. It must also have the ability to protect a warhead as it re-enters the atmosphere, and it is not clear if North Korea can do that.

What does this test tell us? By defence expert Melissa Hanham

Once again North Korea has defied the odds and thumbed its nose at the world in a single missile launch. With the test of the Hwasong-14, it has shown that it can likely reach intercontinental ballistic missile ranges, including putting Alaska at risk.

Kim Jong-un has long expressed his desire for such a test, and to have it on the 4 July holiday in the US is just the icing on his very large cake.

Image copyrightREUTERS

Image captionNorth Korean state TV released photos of the purported ICBM test launch

Despite this technical achievement, however, it is likely many outside North Korea will continue to be sceptical. They will ask for proof of working guidance, re-entry vehicle, and even a nuclear warhead.

From a technical perspective, though, their engines have demonstrated ICBM ranges, and this would be the first of several paths North Korea has to an ICBM with even greater range.

North Korea's missile programme

What is an ICBM?

• A long-range missile usually designed to carry a nuclear warhead
• The minimum range is 5,500km (3,400 miles), although most fly about 10,000km or more
• Pyongyang has previously displayed two types of ICBMs: the KN-08, with a range of 11,500km, and the KN-14, with a range of 10,000km, but before 4 July had not claimed to have flight tested an ICBM. It is not clear what differentiates the Hwasong-14

Are neighbours and nuclear powers concerned?

South Korea's President Moon Jae-in has called on the United Nations Security Council to take steps against North Korea.

But a strong warning came from the country's Director of Operations of the Joint Chiefs of Staff. Cho Han-Gya said "Kim Jong Un's regime will face destruction" if it "ignores our military's warnings and continues provocations".

Japan said "repeated provocations like this are absolutely unacceptable" and Prime Minister Shinzo Abe said his country would "unite strongly" with the US and South Korea to put pressure on Pyongyang.

US President Donald Trump also responded swiftly on Tuesday.

On his Twitter account he made apparent reference to North Korean leader Kim Jong-un, saying: "Does this guy have anything better to do with his life?

"Hard to believe that South Korea and Japan will put up with this much longer. Perhaps China will put a heavy move on North Korea and end this nonsense once and for all!"

Image copyrightKCNA/REUTERS

Image captionNorth Korean state TV said the launch was overseen by leader Kim Jong-un

President Trump has repeatedly called on China, Pyongyang's closest economic ally, to pressure North Korea to end its nuclear and missile programmes.

On the prospect of North Korea being able to strike the US, he tweeted in January: "It won't happen." However experts say it might - within five years or less.

Meanwhile, UK Foreign Secretary Boris Johnson said the international community "must redouble its efforts to impose a price on this regime, which strains every nerve and sinew to build nuclear weapons and launch illegal missiles, even as the people of North Korea endure starvation and poverty".

BBC NEWS

Scientists explain ancient Rome's long-lasting concrete

Researchers have unlocked the chemistry of Roman concrete which has resisted the elements for thousands of years.

Ancient sea walls built by the Romans used a concrete made from lime and volcanic ash to bind with rocks.

Now scientists have discovered that elements within the volcanic material reacted with sea water to strengthen the construction.

They believe the discovery could lead to more environmentally friendly building materials.

Unlike the modern concrete mixture which erodes over time, the Roman substance has long puzzled researchers.

Rather than eroding, particularly in the presence of sea water, the material seems to gain strength from the exposure.

In previous tests with samples from ancient Roman sea walls and harbours, researchers learned that the concrete contained a rare mineral called aluminium tobermorite.

They believe that this strengthening substance crystallised in the lime as the Roman mixture generated heat when exposed to sea water.

Researchers have now carried out a more detailed examination of the harbour samples using an electron microscope to map the distribution of elements. They also used two other techniques, X-ray micro-diffraction and Raman spectroscopy, to gain a deeper understanding of the chemistry at play.

This new study says the scientists found significant amounts of tobermorite growing through the fabric of the concrete, with a related, porous mineral called phillipsite.

The researchers say that the long-term exposure to sea water helped these crystals to keep on growing over time, reinforcing the concrete and preventing cracks from developing.

"Contrary to the principles of modern cement-based concrete," said co-author Marie Jackson from the University of Utah, US, "the Romans created a rock-like concrete that thrives in open chemical exchange with seawater."

"It's a very rare occurrence in the Earth."

The ancient mixture differs greatly from the current approach. Modern buildings are constructed with concrete based on Portland cement.

This involves heating and crushing a mixture of several ingredients including limestone, sandstone, ash, chalk, iron and clay. The fine material is then mixed with "aggregates", such as rocks or sand, to build concrete structures.

The process of making cement has a heavy environmental penalty, being responsible for around 5% of global emissions of CO2.

So could the greater understanding of the ancient Roman mixture lead to greener building materials?

Prof Jackson is testing new materials using sea water and volcanic rock from the western United States. Speaking to the BBC earlier this year, she argued that the planned Swansea tidal lagoon should be built using the ancient Roman knowledge of concrete.

"Their technique was based on building very massive structures that are really quite environmentally sustainable and very long-lasting," she said.

"I think Roman concrete or a type of it would be a very good choice [for Swansea]. That project is going to require 120 years of service life to amortise [pay back] the investment.

"We know that Portland cement concretes contain steel reinforcements. Those will surely corrode in at least half of that service lifetime."

There are a number of limiting factors that make the revival of the Roman approach very challenging. One is the lack of suitable volcanic rocks. The Romans, the scientists say, were fortunate that the right materials were on their doorstep.

Another drawback is the lack of the precise mixture that the Romans followed. It might take years of experimenting to discover the full formula.

The research has been published in the journal American Mineralogist.

Follow Matt on Twitter 

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