The volcano on the Italian island of Stromboli has erupted again, two months after similar activity killed a tourist.
Fiery chunks of lava have been thrown from the crater and an ash cloud climbing to more than a kilometre high.
The National Institute of Geophysics and Volcanology says a strong volcanic explosion at around noon Wednesday sent flaming lava rolling down the volcano's slopes to the edge of the sea.
This "high intensity" explosion was very similar to the eruption in July on Stromboli which killed a 35-year-old Italian hiker.
There were no immediate reports of injuries. Some small fires were reported near one of the Mediterranean island's hamlets.
This latest eruption has produced a disturbing event known as a "pyroclastic flow" – a fast moving flow of superheated rock and gas – to come cascading into the sea, according to CNN.
A similar event is thought to have occurred 2000 years ago on the Italian mainland near Naples, engulfing Pompeii and Herculaneum.
The islands popularity among tourists ensured that there were plenty of witnesses. One, Marietta Daviz captured the moment on twitter.
Elsewhere tourists have been fleeing the tiny island and resorts which have only recently been cleared of ash from the previous explosion.
One video shared with the UK Telegraph, showed a family of British tourists watching from a boat in fear for their lives.
"Wow! The whole mountain is shaking!" a man can be overheard as saying. "Oh my goodness, that is really bad, guys."
Elena Schiera, from Sicily, told CNN she was also on a boat during the eruption:
"We were sailing at a safe distance as per ordinance when all of a sudden we heard a loud bang and saw a large black cloud spewing out of the Stromboli crater and pouring into the sea," she said.
"We immediately increased the speed of the boat to the maximum, even though, being a sailboat, the speed was still limited. Then the cloud arrived at sea and began to advance quickly towards us.
"At that moment the panic broke out because we had the cloud a few metres away from our stern, but thanks to my father who was at the helm, we managed to get away just in time because then the cloud started to rise again."
Stromboli, population 400, is 217 kilometers southeast of Naples in the Aeolian archipelago and is one of three active Italian volcanoes.
"The situation is under control, but all the same we have activated the normal civil protection procedures," said Marco Giorgianni, the mayor of Lipari, the island's main town.
Rumbling almost continuously, Stromboli sends out streams of lava, whose red-hot glows can be seen from offshore at night.
- With reporting by AP