MADRID (Reuters) – Authorities on the Spanish island of La Palma on Wednesday lifted lockdown on three coastal towns as toxic fumes from the lava flowing into the sea partly dissipated, but the eruption of the Cumbre Vieja volcano showed no signs of abating.

The red-hot molten rock continued to gush along the western flanks of the volcano, which has been erupting since Sept. 19, and the pace of daily earth tremors is yet to slow down.

La Palma airport remained closed since the weekend, and footage released by airport operator Aena showed staff shovelings tonnes of black ash from the runway.

“If the eruption intensity doesn’t diminish, it is most likely to keep affecting La Palma airport,” said Carmen Lopez, who heads the National Geographic Institute’s geophysical monitoring program.

Local authorities on Monday forced residents of three coastal towns to stay indoors as a third tongue of lava hit the sea sending thick clouds of vapor and smoke high into the sky.

The cloud is less dense now, said Miguel Angel Morcuende, technical director of the Canary Islands Volcanic Emergency Plan.

“However, we recommend that people living near where the lava flow reaches the sea to wear the FFP2 masks and stay protected to prevent any problem,” he told reporters.

The lava solidifying as it crashes into the water has expanded the island’s surface by some 46 hectares, according to the authorities.

It has engulfed 1,073 hectares of land so far, according to the EU satellite monitoring system Copernicus. The eruption has damaged or destroyed nearly 2,700 buildings, forcing the evacuation of thousands from their homes on the island.

(Reporting by Inti Landauro and Emma Pinedo, editing by Andrei Khalip and Mike Collett-White)