LA PALMA: A volcano on Spain's La Palma island began ejecting lava again after a lull, while hundreds of people in coastal villages hunkered down in anticipation of lava emitted in previous days reaching the sea and releasing toxic gas.

Spurts of vivid lava emerged from the Cumbre Vieja volcano in the early evening and snaked down the dark mountainside after a period of several hours without explosions, according to Reuters witnesses.

The hiatus and new explosions came eight days after lava started pouring from the mountain range on the island, which neighbours Tenerife in the Canary Islands archipelago off North Africa.

"Activating and deactivating is logical, natural in the evolution of Strombolian volcanoes," said Miguel Angel Morcuende, director of the Pevolca response committee, referring to the type of violent eruption that emits incandescent dust.

His Pevolca colleague, Maria Jose Blanco, said lower levels of gas and a reduced supply of material within the crater could have caused the drop in activity.

Since Sept. 19, black lava has been slowly flowing down the volcano's western flank toward the sea, destroying more than 500 houses as well as churches and banana plantations, according to the European Union's Copernicus disaster monitoring programme.

Spanish property portal Idealista estimated the damage at around 178 million euros ($209 million) on Monday.

On Monday, two tongues of the superheated black lava were rounding a hill to the west of the small town of Todoque, less than a kilometre from the Atlantic, but authorities said they could not be sure when it might reach the sea.

Still, about 300 local residents in the coastal areas of San Borondon, Marina Alta and Baja and La Condesa have been confined to their homes as the moment of contact between the lava and the sea is likely to trigger explosions and emit clouds of chlorine gas.

Local airline Binter, which had planned to resume flights to and from the islands on Monday afternoon, said conditions were still unsafe and that all transfers would be cancelled until Tuesday.

After a new vent opened on Sunday, Reuters drone footage showed a river of red hot lava flowing down the slopes of the crater, passing over homes, and swathes of land and buildings engulfed by a black mass of slower-moving, older lava.

No fatalities or serious injuries have been reported, but about 15% of the island's banana crop could be at risk, jeopardising thousands of jobs.

La Palma's population numbers over 83,000.