More than 700 flats in tower blocks on an estate in the Swiss Cottage area of north-west London have been evacuated because of fire safety concerns.
Camden Council said people in four towers on the Chalcots estate were moved for "urgent fire safety works".
The council added it was booking hotels but around 100 residents have spent the night on air beds in a leisure centre.
The estate's cladding is similar to Grenfell Tower in west London, where a fire is feared to have killed 79.
Chalcots was refurbished between 2006 and 2009 by the same firm, Rydon, that oversaw work at Grenfell Tower in 2015-16.
Camden Council said it will remove external thermal cladding from five tower blocks on the Chalcots estate.
It also said there were concerns about the insulation of gas pipes going into flats, and fire doors.
The council initially announced the evacuation of one tower block, Taplow, but later extended the move to all five tower blocks it had checked.
In the early hours of Saturday morning, the council then announced that one of the five - Blashford - did not need to be evacuated, and residents could return.
Blashford is smaller and has "several different design elements".
Residents of the estate attended a public meeting with council officials on Thursday evening.
The council's Labour leader, Georgia Gould, said the decision to evacuate the buildings was made at 18:30 BST on Friday.
She said the fire service "told us they could not guarantee our residents' safety in those blocks".
Some residents said the first they heard of the evacuation was on the news.
The council has secured 270 hotel rooms so far. Emergency accommodation was set up at Swiss Cottage leisure centre and at the Camden Centre in King's Cross.
"We're encouraging all residents to stay with friends and family if they can, otherwise we'll provide accommodation," the council said.
"I know it's difficult, but Grenfell changes everything and I just don't believe we can take any risk with our residents' safety and I have to put them first," Ms Gould said.
She said the work is expected to take three to four weeks. Residents will be allowed in at the weekend to collect more possessions under escort from the fire brigade.
Prime Minister Theresa May tweeted: "My thoughts are with residents being evacuated in Camden while their homes are made safe tonight."
She said the government was "offering every support we can" to residents and officials working at the estate.
At the scene
Alex Regan, BBC News
As the sun set on Swiss Cottage, there was frustration among residents of the Chalcots estate.
With tower blocks being evacuated, the streets were teeming with neighbours, children, and cameramen.
Camden Council employees wearing hi-viz vests stood outside the Taplow tower, speaking to residents.
Some of them only realised their homes were being evacuated after hearing news reports.
Most were not in the mood to talk. One woman shouted angrily at a TV cameraman: "Can you tell me what's going on?"
Teacher Kim Price, who lives in Blashford tower with her 14-year-old son, said: "At 4pm today they said it would be okay and that all the checks were fine.
"And now all of a sudden the news is saying we should get out.
"We've had two letters in two days saying 'you're not safe' then 'you're safe'. I don't really know what to do."
Edward Strange, who lives in an 11th floor flat with his wife and young daughter, said the evacuation was a "complete overreaction".
He told the BBC there had been two previous fires in the block which were easily contained.
"I've got a young daughter, a wife and a cat, I've also got a job. They said it'd take four to six weeks. If the council says four to six weeks it'll take four to six months."
Among those evacuated was Peter Bertram, 94, who has lived on the estate for 46 years.
The former RAF airman, who served in World War Two, said having to leave his home at short notice was a "shock".
"My neighbour told me 'Get this and that'. It happened so quick, I don't have the energy for that now. It's an experience."
Bob O'Toole, chair of Chalcots Estate residents' association, told BBC Breakfast that contractors had been working overnight in several of the tower blocks.
"A lot of people are annoyed because of the way [the evacuation] was done. They're saying it was left too late in the evening. But Camden Council didn't get the information till late, and they acted on that as quickly as possible."
Communities Secretary Sajid Javid said other areas, such as Plymouth and Manchester, had seen measures introduced such as 24-hour fire wardens and did not need evacuating.
"What was very different here is that the local fire service found multiple other failures in fire safety that should have already been in place in the towers, and as a result of that, they've made this quite correct decision."
Mr Javid also said the government would "work with" any local authorities and housing associations that needed financial support to carry out necessary fire safety work in tower blocks.
"Public safety is absolutely paramount, you cannot put a price on people's lives. So local authorities have to do whatever it takes to get their buildings safe."
Rebecca Long-Bailey, the shadow business secretary, said people who were in towers where cladding was being investigated would be "living in fear".
"I've had hundreds of constituents contacting my office over the last week, asking whether the buildings they're living in are safe.
"People need to give significant weight to the voice of residents, and if they do want to be moved, if they feel unsafe and haven't been reassured, then provision should be put in place [to move them]."
Camden Council agreed a contract with Rydon Construction to refurbish the Chalcots estate in May 2006 at a cost of £66m.
The work took more than three and a half years. Five towers received new cladding, and 711 flats were modernised with new wiring, heating, kitchens and bathrooms.
Friday night's announcement came as the Metropolitan Police said the Grenfell Tower fire started in a fridge-freezer, and outside cladding and insulation failed safety tests.
A national operation to identify buildings with cladding similar to that used in Grenfell Tower has seen local authorities send samples for independent tests.
The Department for Communities and Local Government said 14 residential high-rise buildings in nine local authority areas have now been found with cladding that raises safety concerns.