The British government said tests are taking place on several hundred buildings to check for flammable exterior panels, like the ones believed linked to the deadly fire at Grenfell Tower in London. (Adrian Dennis/Agence France-Presse via Getty Images )

The British government said Thursday that tests were underway on about 600 buildings across England to check for flammable exterior panels similar to those believed to be linked to a deadly fire that quickly engulfed a London tower last week.

The testing is part of an investigation into the fast-moving inferno at the Grenfell Tower, which claimed at least 79 lives and raised questions about whether the building’s outside covering, known as cladding, could have contributed to the blaze.

British Prime Minister Theresa May said that as a precaution, the cladding in similar tower blocks was being tested. Britain has around 4,000 similar high-rise apartment blocks across the country.

A report from local councils, which administer many housing developments, found about 600 high-rise buildings have cladding.

The government is testing 600 buildings with cladding that are at least 18 meters tall (59 feet), said a Department of Communities and Local Government spokeswoman, who did not give her name in accordance with customary briefing rules.

She said that earlier reports from Downing Street — saying that 600 buildings could have “similar cladding” to the Grenfell fire — was an initial misunderstanding of the report.

Speaking to the House of Commons, May said fire officials have been told of the report and “are taking all possible steps to ensure buildings are safe and to inform affected residents.”

“We cannot and will not allow people to live in unsafe homes,” she said.

British media outlets have reported that the cladding on Grenfell Tower — added during a major renovation last year — was aluminum composite cladding that has a plastic core.

This model of cladding, which covered the exterior of the building, reportedly cost about 5,000 pounds ($6,300) less than a more fire-resistant version.

A Downing Street spokeswoman said that samples from the 600 buildings need to be tested and that the testing facility can handle about 100 samples a day. So far, seven have been found to have potentially combustible cladding.

The government has not named the seven buildings. But a local council in north London said on Thursday that it was removing cladding on five tower blocks on the Chalcots Estate in Swiss Cottage, an area in northwest London’s Camden borough. They also pledged round-the-clock fire safety patrols to reassure residents.

“The new results from the laboratory show that the outer cladding panels themselves are made up of aluminum panels with a polyethylene core,” Georgia Gould, leader of the Camden council, said in a statement.

The panels were “not to the standard that we had commissioned,” Gould said. She added that the council was seeking legal advice.

Muitun Begum, 42, a volunteer child-care worker who lives in one of the towers, welcomed the new safety measures. But she said knowing her family is living in a building with potentially flammable cladding was unnerving.

“It is making me feel worried,” she said, sitting at her living room table reading over letters from the council. Of the Grenfell fire, she said: “Everyone is talking about it: Why did it go up so quick? It went up like paper. Now we are worried that we are not safe.”

When asked if the cladding on Grenfell Tower was compliant with Britain’s building regulations for a building of its height, May said that an investigation was underway and that the police and fire services would make a relevant statement this week.

She said Grenfell residents, many of whom are staying in hotels, will be moved to new housing within three weeks. She added that no immigration checks will be carried out on the residents or those providing information to help identify the victims.

There have been reports that some of the tenants were illegally subletting their apartments or were illegal immigrants and that people have been scared to come forward.

London’s Metropolitan Police Department has opened a criminal investigation into the blaze that could result in prosecutions for those deemed responsible.

“For any guilty parties there will be nowhere to hide,” May told lawmakers.

Her statement follows the resignation of the chief executive of the council that runs the borough where the Grenfell fire took place.

Nicholas Holgate, chief executive of the Kensington and Chelsea council, left his post after the council came under intense criticism for alleged failings before and after the fire.