91�ȱ�

Lava flowing from an erupting volcano in the Canary Islands has reached the ocean.

Clouds of white steam were seen rising as the red-hot liquid rock made contact with the water.

There are now concerns that toxic gases could be released into the air.

Thousands of people have already been evacuated to safety from the island of La Palma where the Cumbre Vieja volcano erupted on 19 September.

The Cumbre Vieja volcano

Lava from the volcano destroyed empty villages, schools and hundreds of homes, as it spewed out from the mountain.

But no serious injuries have been reported on the island and nobody has been killed since the eruption began.

In anticipation of the lava making contact with the water, three nearby coastal villages have been locked down, with residents told to stay inside for their safety.

Authorities have also set up an exclusion zone around the lava, including in the sea, to keep people away from any potential danger.

The Spanish government has declared La Palma a disaster zone and has promised financial support for all those affected by the volcanic activity.

Why is lava reaching the sea a problem?

When lava comes into contact with ocean water, it produces a gas plume known as laze - lava and haze.

Laze forms after a series of chemical reactions when hot lava boils the colder sea water.

"It creates a steam of hydrochloric acid, water vapour and bits of ash," said science journalist and volcanologist Dr Robin George Andrews.

"Obviously, it's not good to breathe in."

Laze plumes can cause eye, lung and skin irritation but should not be a problem if island residents keep their distance, he said.

'Explosions possible'

Dr Robin says that volcanic explosions were also possible, because lava entering water creates steam very quickly and "a pressure-cooker situation" that "might fling out volcanic debris".

This is also more likely if huge chunks of red hot rock suddenly fall into the sea, something officials are concerned about with coastal cliffs in danger of collapsing.

For several days officials had predicted the lava would reach the ocean. Although volcanic activity calmed down on Monday, the volcano became more explosive overnight on Tuesday.

According to the Canary Island Volcanology Institute, the volcano has so far ejected more than 46 million cubic metres (1.6 billion cubic feet) of molten rock - which is the equivalent of more than 120,000 25 metre swimming pools.