Italy's Stromboli volcano has exploded in front of holidaymakers, spewing an ash cloud and rocks, sending a river of lava into the sea and setting vegetation on fire.
The eruption appeared to be more powerful than one in July which killed a hiker and forced terrified tourists to dive into the sea as rocks rained down.
The summit of Stromboli - one of the most active volcanoes in the world - had already been closed due to an increase in activity this summer, including smaller explosions this week.
Londoner Nicole Bremner, who witnessed Wednesday's eruption, tweeted: "We were just at #Stromboli volcano watching the small eruptions. We left and then this giant eruption happened!
"A couple of smaller eruptions now and this metallic taste in our mouths. Waiting to see if we need to help with evacuations."
Did you witness the eruption? Email webnews@mirror.co.uk.
Tourists gathered to watch the ash cloud billow into the sky and lava slide down the side of the volcano after a huge roar that was heard for miles around.
The volcano is on the small island of Stromboli in the Tyrrhenian Sea off the north coast of Sicily.
With a population of about 500, the island has holiday homes and is a popular destination for the rich and famous and British holidaymakers.
Stromboli's "major explosion" happened just after 12pm local time and it appeared to be stronger than the July 3 eruption, Volcano Discovery reported.
The website reported: "It was another massive explosion from the summit vents, producing an ash plume that rose probably a few km, ejected bombs to the upper slopes of the volcano and caused a pyroclastic flow that traveled down the Sciara into the sea.
"Activity had been very high during the past weeks and the summit area was already closed, which hopefully prevented any injuries or worse.
"From webcam images, nothing very unusual could be detected in the minutes before, just a relatively strong (but not unusual) eruption from a vent in the northeastern crater at 11:55 local time."
It said the eastern and north-eastern sides of the volcano above the village of Stromboli were hit by more "bombs" than the July 3 eruption.
Some witnesses estimated that Wednesday's eruption was stronger than the one two months ago, Ansa reported.
Related video: Stromboli erupts in July
In that explosion, a male hiker was killed by a falling rock, several people were injured and terrified holidaymakers ran for their lives or jumped into the sea.
The victim was a 35-year-old man from Sicily.
About 70 people were evacuated.
Before then, the last major eruption happened in 2002, when local buildings and piers were destroyed and six people were injured.
Known as the "Lighthouse of the Mediterranean", Stromboli is one of three active volcanoes in Italy and it has been in a regular state of eruption since 1932.
The other two are Mount Etna and Mount Vesuvius.
