The Cumbre Vieja volcano, which began erupting last Sunday, is entering a new explosive phase. The Canary Islands Volcanology Institute, Involcan, said the new emission vent that had opened was to the west of the principle vent.

The national Geographical and Mining Institute said its drones had shown the volcano’s cone had broken.

“It is not unusual in this type of eruption that the cone of the volcano fractures. A crater is formed that does not support its own weight and … the cone breaks,” Miguel Angel Morcuende, director of volcano response committee Pevolca, told a news conference on Saturday. “This partial rupture happened overnight.” Morcuende said the evacuations currently in place would be maintained for another 24 hours as a precaution.

The volcano has spewed out thousands of tons of lava, destroyed hundreds of houses and forced the evacuation of nearly 6,000 people since it began erupting on last Sunday. La Palma, with a population of over 83,000, is one of an archipelago making up the Canary Islands in the Atlantic. Spanish airport operator Aena said the island’s airport had closed.

“La Palma airport is inoperative due to ash accumulation. Cleaning tasks have started, but the situation may change at any time,” it tweeted.

Workers swept volcanic ash off the runway, electronic boards showed cancelled flights and the departures hall was quiet as some people arriving at the airport discovered they would not be able to fly out.

There were long queues at La Palma’s main port as people, some whose flights had been cancelled, tried to get ferries off the island.

“I am going to Barcelona. But because we can’t fly we are taking the ferry to Los Cristianos (on Tenerife island) and from there we will go to the airport and fly to Barcelona,” said Carlos Garcia, 47.

People evacuated from three more towns on Friday will not be able to return to their homes to retrieve their belongings because of the “evolution of the volcanic emergency,” local authorities said.