LONDON — Britain’s prime minister on Tuesday ordered an investigation into cladding and insulation on high-rise towers across the country, as authorities struggled to contain the risk from construction materials that leave tall structures vulnerable to catastrophic fires.

The government revealed that 95 buildings, in 32 areas, had used cladding and insulation similar to those installed at Grenfell Tower, the West London apartment building that was consumed by flames on June 14 in Britain’s deadliest fire in decades. All 95 buildings fell short in safety tests — “a 100 percent failure rate,’’ according to a spokesman for Prime Minister Theresa May. Hundreds of other tall buildings are still being tested.

The cladding on the 95 buildings will almost certainly have to be replaced. Such work has already begun on a complex of towers in the Salford area near Manchester. Last week, the London borough of Camden ordered the evacuation of 4,000 residents of a five-tower complex, where the buildings were covered in the flammable cladding.

Anxiety about the building materials appeared to be spreading to other countries, even though the United States and most countries in Europe had restrictions on the kind of cladding used on Grenfell Tower. The German city of Wuppertal on Tuesday evacuated about 80 people from an 11-story apartment tower after “flammable material was found,’’ a local official said.

Arconic, the US company that sold the combustible material, said Monday that it would no longer sell the paneling for use in high-rises.

New York Times