LONDON — The scope of Britain’s fire-safety crisis broadened Saturday, as London officials scrambled to evacuate four public housing towers due to concerns about fire doors and insulation around gas pipes, leaving residents angry and confused.

Camden Council said it decided to evacuate the buildings on the Chalcots Estate after fire inspectors told officials they couldn’t guarantee the safety of residents. Inspectors uncovered problems with “gas insulation and door stops,” which combined with the presence of flammable cladding meant the buildings were unsafe, council Leader Georgia Gould said in a tweet.

Camden council said about 650 apartments were evacuated.

Meanwhile, the national government said Saturday that cladding samples from 27 high-rise apartment blocks in 15 areas have failed fire safety tests.

That expands the focus beyond the external cladding blamed for the rapid spread of a deadly inferno in on June 14. The blaze that engulfed Grenfell Tower killed at least 79 people.