British Prime Minister Theresa May's office says around 600 buildings in England have cladding similar to the type blamed for the quick spread of flames in the London high-rise disaster.
Councils in England made the estimate as authorities desperately try to get a grip on the scale of the issue facing local authorities following the blaze at Grenfell Tower that killed at least 79 people on June 14.
The cladding on the building has been singled out for scrutiny because the blaze engulfed the building in less than an hour. That has surprised fire officials, who have wondered aloud how a 24-story building could become an inferno so quickly.
Flames spread rapidly up tower block, trapping people inside, in what was Britain's worst blaze since World War II. Exterior cladding added during a refurbishment may have played a part, residents have said.
"(We) should of course be careful on speculating what caused this fire, but as a precaution the government has arranged to test cladding on all relevant tower blocks," May told parliament.
"Shortly before I came to the chamber, I was informed that a number of these tests have come back as combustible."
She said local authorities and fire services have been informed and are taking steps to make affected buildings safe and to inform residents.
May has launched a public inquiry into the fire and police have announced a criminal investigation.
May said tests on the cladding of Grenfell Tower where the fire blazed would be made public in the next 48 hours.
"This has been a wake-up call for the whole country," said Jeremy Corbyn, leader of the opposition Labour Party.
After apologising for a slow state response to the fire, May also said it was appropriate that the head of the local council had resigned over the fire.
Nicholas Holgate, chief executive of Kensington and Chelsea council, said he was forced out by the government.
Reuters/AP
