The White House has defended President Donald Trump's reaction to deadly violence over a white supremacist rally in Virginia, amid criticism he did not explicitly condemn far-right groups.
But a spokesman said his condemnation included white supremacists.
A woman was killed on Saturday when a car rammed into a crowd protesting against the rally in Charlottesville.
Separately, a rally organiser was chased away by protesters as he tried to give a press conference on Sunday.
Jason Kessler, who organised the controversial "Unite the Right" march, was heckled and booed as he blamed the police for not preventing the violence, which he also condemned.
Nineteen people were injured in the car-ramming incident, and another 15 people were wounded in separate clashes related to the far-right march on Saturday afternoon.
Protests and vigils in support of Charlottesville were held in many US cities on Sunday. In Seattle, police used pepper spray to stop anti-fascist protesters approaching a pro-Trump rally.
How did Trump initially respond?
Hours after the violence erupted, Mr Trump said he condemned "in the strongest possible terms this egregious display of hatred, bigotry, and violence on many sides".
"The hate and the division must stop right now," he told reporters in New Jersey, where he is on a working holiday. "We have to come together as Americans with love for our nation."
But his comments did not explicitly condemn the white extremist groups involved in the rally, an omission that was strongly criticised by Republicans and Democrats alike.
Floods caused by rivers impact more people than any other natural hazard, and the estimated global damages run to over a $100bn a year.
Researchers have long predicted that a warming world would have direct impacts on these events but until now the evidence has been hard to establish.
Floods are affected by many different factors in addition to rainfall, such as the amount of moisture already in the soil and other questions such as changes in land-use that can speed up water run-off from hillsides.
This new study looks at this issue in some depth, by creating a Europe-wide database of observations from 4,262 hydrometric stations in 38 countries, dating back to 1960.
The analysis finds a clear but complex impact of climate change on river flooding.
The most consistent changes are in north-eastern Europe around Scandinavia where earlier snow melt due to warmer temperatures is leading to earlier spring floods. Around 50% of monitoring stations are seeing floods eight days earlier than they did 50 years ago.
The biggest changes are seen along the western edge of Europe, from Portugal up to Southern England. Half the stations recorded floods at least 15 days earlier than previously. A quarter of the stations saw flooding more than 36 days earlier than in 1960.
In these regions, the issue isn't snow melt - it's more about saturated soils. Maximum rainfall tends to occur in the autumn and gets stored in the soils. Heavier and earlier rain means that the groundwater reaches capacity earlier.
"It's the interplay between extreme rainfall and the abundance of rainfall," lead author Prof Günter Blöschl, from the Technical University of Vienna, told BBC News.
"In southern England, it has been raining more, longer and more intensely than in the past. This has created a rising groundwater table and higher soil moisture than usual and combined with intense rainfall this produces earlier river floods."
However, around the North Sea, in the Netherlands, Denmark and Scotland, the trend is towards later floods.
The scientists believe this is due to changes in the North Atlantic Oscillation (NAO), the weather phenomenon that pushes storms across the ocean into Europe.
The NAO is driven by differences in atmospheric pressure between the North Pole and the Equator. Recent, rapid changes in temperatures in the Arctic are interfering with these pressure levels and changing the track of the oscillation and storms as well.
According to this study, the storms are arriving later and as a result some river flooding happens later too.
Prof Blöschl says that this study shows clear evidence of the impact of human-induced climate change in many regions - but there are still some areas of uncertainty.
"Where the human imprint is obvious is in the northeast of Europe. It is quite a direct link, with a warming climate and earlier snow melt," he said.
"However, the areas impacted by the NAO are more difficult to attribute to anthropogenic global warming. The jury is still out on that aspect."
The study foresees subtle but significant impacts that could arise from the change in flood timing. There could be effects on river ecosystems with salmon spawning later in the year. There could also be implications for hydropower stations, and for agriculture if fields stay wetter for longer.
The more serious concern is that if warming impacts the seasonality it may also impact the scale of flooding," said Prof Blöschl.
"You could think of timing changes as the harbinger of future changes of flood magnitude. That is the more serious concern. If that happens, flood risk management will have to adapt and that will be different in different parts of Europe."
Other experts believe that the changes in flood timing identified by this study have significant implications for how we understand the risk of river floods and how we deal with them.
"Nearly every major city and town in Europe is built on a river and we protect this urban infrastructure by using past floods as a gauge of the potential risk," said Mark Maslin, Professor of Climatology at University College London.
"The study shows that this approach underestimates the risk, as climate change has made European floods occur earlier in the year, increasing their potential impact.
"This means all the infrastructure that we have built to protect our cities needs to be reviewed as much of it will be inadequate to protect us from future climate change-induced extreme flooding."
Spain may overtake Greece this year in numbers of migrants arriving clandestinely by sea, the International Organization for Migration (IOM) says.
So far in 2017, 8,385 people have reached the country by sea, more than triple the number seen at the same time in 2016. Greece has had 11,713 people.
The shift may be because migrants are finding the Spanish route safer.
Meanwhile, 10 men from sub-Saharan Africa were rescued off the coast of Spain.
The coastguard said they were on a rickety boat off the southern town of Tarifa, in Cádiz province, where a boat full of migrants landed at a popular tourist beach on Wednesday, stunning tourists.
Despite seeing an increase in arrivals, Spain is still far behind Italy, which has received 96,861 until 9 August, according to the IOM.
"We assume that some of the change is due to the fact that the route [to Spain] is considered a safe route up to the coast through Morocco," Joel Millman, a senior IOM spokesman, was quoted by AFP news agency as saying.
Many of those opting for the longer route are from west African countries including Senegal, Gambia, Guinea and Ivory Coast.
Some 11,849 people have arrived in Spain so far this year, compared to 13,246 in all of last year, the IOM says.
According to AFP, nine of the 30 or so migrants who arrived on the beach on Wednesday had been found.
They are all minors in their teens and, while they did not have any ID on them, are thought to be from Morocco, police were quoted as saying .
They will be taken to migrant reception centres, where they can apply for asylum in Spain, AFP adds.
A note on terminology: The BBC uses the term migrant to refer to all people on the move who have yet to complete the legal process of claiming asylum. This group includes people fleeing war-torn countries such as Syria, who are likely to be granted refugee status, as well as people who are seeking jobs and better lives, who governments are likely to rule are economic migrants.
President Donald Trump has warned North Korea it should be "very, very nervous" if it does anything to the US.
He said the regime would be in trouble "like few nations have ever been" if they do not "get their act together".
His comments came after Pyongyang announced it had a plan to fire four missiles near the US territory of Guam.
US Defence Secretary James Mattis warned that armed conflict with North Korea would be "catastrophic" and said diplomacy was bearing fruit.
"The American effort is diplomatically led, it has diplomatic traction, it is gaining diplomatic results," he said.
Australian Prime Minister Malcolm Turnbull has said his country is fully prepared to join a war against North Korea, were it to launch an attack on the US.
"If there's an attack on the US, the Anzus Treaty would be invoked and Australia would come to the aid of the United States," he said in a radio interview, "as America would come to our aid if we were attacked."
Tensions have escalated in recent weeks after North Korea tested two intercontinental ballistic missiles in July.
The UN recently approved further economic sanctions against Pyongyang over its nuclear weapons programme.
President Trump also said he was close to revealing his keenly awaited decision on the number of troops he plans to keep in Afghanistan.
He said he had "taken over a mess", but was going to make it "a lot less messy".
Speaking on Thursday at his golf club in Bedminster, New Jersey, Mr Trump suggested his own statements on North Korea had not been tough enough, despite his threat this week to rain "fire and fury" upon the regime.
North Korea has dismissed his dire warnings as "nonsense".
Mr Trump railed against previous US administrations for being too weak on North Korea and also chided the North's closest ally, China, saying it could do "a lot more".
He said: "I will tell you this, if North Korea does anything in terms of even thinking about attack of anybody that we love or we represent or our allies or us they can be very, very nervous.
"I'll tell you why… because things will happen to them like they never thought possible."
However, he added that the US would always consider negotiations.
He added: "I will tell you this, North Korea better get their act together or they're gonna be in trouble like few nations have ever been."
However, there has been no indication that any attack on the Pacific island is imminent.
Analysis: Jitters in South Korea
Yogita Limaye, BBC News, Seoul
On the streets of Seoul, barely 50km (30 miles) from the border with North Korea, the latest developments have drawn mixed reactions. Kim Seong-su, 62, said he thought Pyongyang was bluffing to preserve its regime and justify its nuclear programme.
But others are more concerned. Yeon Eui-sook says she finds the situation scary. "I hope everyone can live in peace. Kim Jong-un keeps doing this and making us worry," she said.
Analysts say the language from Pyongyang always gets more aggressive in August, when the US and South Korea conduct joint military exercises. But this time - with a US president who also uses strong words - the confrontation is getting even fiercer than usual.
Mr Trump meanwhile denied there were any mixed messages from his administration.
Earlier this week, US Secretary of State Rex Tillerson played down the rhetoric between the two sides.
But in an interview with the BBC on Thursday, White House Deputy Assistant Sebastian Gorka dismissed the top diplomat's comments.
"You should listen to the president," he said. "The idea that Secretary Tillerson is going to discuss military matters is simply nonsensical."
Mr Gorka recalled a quote from a Holocaust survivor he often refers to when lecturing on grand strategy, saying: "When a group of people repeatedly says they want to kill you, sooner or later you should take them seriously".
"North Korea has said they wish to annihilate the United States and use nuclear weapons. Sooner or later, somebody should take them seriously," he said.
The tiny but important island of Guam
The 541sq km (209 sq miles) volcanic and coral island in the Pacific between the Philippines and Hawaii.
It is a "non-incorporated" US territory, with a population of about 163,000.
That means people born in Guam are US citizens, have an elected governor and House Representative, but cannot vote for a president in US national elections.
US military bases cover about a quarter of the island. About 6,000 personnel are based there and there are plans to move in thousands more.
It was a key US base in World War Two, and remains a vital staging post for US operations, giving access to potential flashpoints like the South China Sea, the Koreas and the Taiwan Straits.