Shocking new footage has shown tourists atop Mount Etna sprinting for safety after clouds of volcanic ash more than four miles high erupted this morning.
A portion of the famous volcano’s southeastern crater is thought to have collapsed shortly after 11am local time this morning, authorities said, triggering an avalanche of molten rock that hurtled down the side of the towering landmark.
Terrified tourists visiting the volcano on the Italian island of Sicily were forced to run for their lives as the gigantic ash cloud plumed behind them.
But the footage also showed some keen holidaymakers refusing to leave until they had stopped to snap a few pictures of the monstrous clouds.
Tourists are able to visit the 3,300m-high Mount Etna in guided tours, though some areas of the volcano can be accessed independently.
A red aviation warning was briefly issued by the Volcanic Ash Advisory Centre after the so-called ‘pyroclastic flow’ occurred at 11:24am local time, as the ash cloud reached 6.5 kilometres (4 miles) in height.
Pyroclastic flows occur when volcanic rock, ash and hot gases surge from volcanoes, often following some kind of tremor or disturbance.
Dr Agust Gudmundsson, from the Department of Earth Sciences at Royal Holloway, University of London, told : ‘Pyroclastic flows, even comparatively small ones, are always dangerous since they move very fast.
‘The origin of this one is not entirely clear, but seems to be partly related to some sort of a collapse.’
Etna, the most active volcano in Europe, had been experiencing some activity with volcanic tremors felt overnight, which experts said likely triggered the continuous ‘explosions of growing intensity’ this morning.
Despite initial warnings, the threat level for aviation has been downgraded to orange in recent hours.
The pyroclastic flow – an avalanche of burning ash careening down the slopes at a fast pace and high density – does not appear to have passed the edge of the Valley of the Lion, one of Etna’s slopes.
The National Institute of Geophysics and Volcanology, Etnean Observatory, said the pyroclastic flow was ‘probably produced by a collapse of material from the northern flank of the South-East Crater’.
A ‘lava fountain’ has also begun after the ash bomb, according to the institute.
The ominous ash cloud is said to mainly consist of water and sulfur dioxide and was ‘drifting towards the southwest’
The National Institute of Geophysics and Volcanology said earlier this morning: ‘Over the past few hours, the activity flagged in the previous statement issued at 4.14am (3.14am BST) has carried on with strombolian explosions of growing intensity that, at the moment, are of strong intensity and nearly continuous.
‘Over the past few hours, the falling of a little thin ash has been flagged in the Piano Vetore area.’
The terrifying volcanic tremor began just after 10pm last night, reaching its peak three hours later at about 2.8km below the crater.
The eruption occurred at 11:24am local time (0924 GMT).
Activity has calmed in the last few hours but the threatening grey cloud is still visible.
Mount Etna, located on the eastern coast of Sicily, is one of the most active volcanoes worldwide and has been going through an especially active period for the last five years.
Last summer, the volcano caused chaos at nearby airports as they were forced to limit and divert flights as pilots struggled with visibility.
A usually busy Catania airport had to send flights to other airports on the island, such as Palermo and Comiso.
Arriving flights were reduced to six per hour and one section of the airport was closed, while local towns were also covered in a blanket of black ash.
The 500,000-year-old volcano has been spewing lava during repeated outbursts in May before today’s explosion.
Etna’s most destructive eruption covered 14 villages and towns in lava flows and earthquakes from the volcano.
The eruption, which lasted several weeks, killed nearly 20,000 people, with thousands more made homeless, according to records from 1669.