New aerial footage of the erupting Hawaii volcano shows fissure 20's fountains spraying magma.

The video, shot on 21 May and released by the United States Geological Survey, reveals the branching lava channels merging closer to the coast.

However, a new threat in the form of a toxic steam cloud has been found and authorities are warning residents to steer clear.

The cloud was formed by a chemical reaction when the lava touched the seawater.

Scientists said the steam turns into clouds at the spots where lava enters the ocean.

The clouds are laced with hydrochloric acid and fine glass particles that can both irritate skin and the eyes, but also cause breathing problems.

The eruptions so far have caused one injury, when a man was hit on the leg by lava splatter.

Authorities have warned that even small pieces of molten rock can kill.