Huge clouds of ash more than a mile high have erupted from Mount Etna, triggered by an avalanche of boiling rock hurtling down the side of the volcano, writes dailymail.co.uk.

Terrified tourists visiting the Italian volcano were forced to run for their lives after a ginormous ash cloud erupted behind them.

Despite horror-struck crowds were seen fleeing, some keen seismologists were stopping on the way down the gravelly slopes to turn back and snap a quick pic of the monstrous clouds.

Residents in nearby towns and cities could see the dramatic cloud begin to dominate the skyline, with ash beginning to settle on buildings and roads.

In one video, the shocking formation begins to blot out the sun. Tourists are able to visit the 3,300m-high Mount Etna in guided tours or access certain areas independently. A red aviation warning was briefly issued by the Volcanic Ash Advisory Centre Toulouse but has now turned to orange. The most active volcano in Europe had been experiencing some activity in the last few hours with volcanic tremors felt overnight but has escalated to continuous "explosions of growing intensity".