Britain said 34 high-rise apartment blocks had failed fire safety checks carried out after the deadly Grenfell Tower blaze, including several in north London where residents were forced to evacuate amid chaotic scenes.

British officials have conducted tests on some 600 high-rise buildings across England after fire ravaged the Grenfell social tower block in west London on June 14, killing at least 79 people in the capital's most deadly blaze since World War Two.

The Department for Communities said 34 apartment blocks had failed tests in 17 parts of the country, from London in the southeast to Manchester in the north and Plymouth on the southwest coast.

Prime Minister Theresa May, who was forced to apologise for the government's initial slow response to the tragedy, said the authorities were now racing to establish what needed to be done.

"In some cases it's possible to take mitigating action," she told Sky news. "In others it's been necessary for people to move out on a temporary basis and that is what happened in Camden last night."

Some 4,000 residents of the Chalcots Estate in Camden, north London, were told to vacate their apartments on Friday after the Fire Brigade ruled that their blocks were unsafe.

Emerging into the streets on a hot night, residents clutched children, pets and small amounts of clothing and food to try to find a bed in a local hotel or with family or friends. Many were directed to inflatable beds laid out on the floor of the local sports hall.

"I know it's difficult but Grenfell changes everything," Georgia Gould, Leader of Camden Council, said in a statement. "I don't believe we can take any risks with our residents' safety."

May said the local authority would be given all the means necessary to make sure people had somewhere to stay.

Residents complained of first hearing about the evacuation from the media and getting very short notice to leave from city officials going door-to-door. Not all residents agreed to go, as they felt the evacuation was an over-reaction.

PUBLIC ANGER

"It was farcical communication," 21-year-old Daniel Tackaberry told Reuters outside a nearby sports centre where the local council had laid out air beds. "You don't get everyone to leave this quickly."

Several local councils said they were removing cladding from the facades of buildings that had failed the tests. In Camden, however, the London Fire Brigade found a number of faults, including concern about cladding, faulty fire doors and holes in compartment walls that could help a fire to spread.

Gould, the Camden council's leader, said it would take up to four weeks to repair the blocks that were evacuated.

Communities Secretary Sajid Javid said the government was working with local authorities and fire services to address any problems that had been found.

"We are now rapidly identifying buildings of concern: samples are being tested very quickly; fire inspectors are checking the safety of the buildings as a whole; and we have issued interim safety guidance," he said.

Police investigating the cause of the 24-storey Grenfell Tower blaze have said the fire started in a fridge but spread rapidly due to external cladding on the building, trapping residents in their beds as they slept.

The cladding has since failed all safety checks and prompted a nationwide review of the materials used on everything from hospitals to hotels and apartment blocks.

The fire has become a flashpoint for public anger at the record of May's Conservative Party in government following cuts to local authority budgets designed to lower the national deficit. Grenfell Tower is located in Kensington, one of the richest boroughs in Europe.

Battling to save her position after losing her majority in a June 8 election, May has promised to do everything she can to protect those residents who survived the fire and to improve the quality and safety of public housing in Britain.

British police have said they are considering bringing manslaughter charges over the Grenfell fire.

Reuters