One dead, six missing after storm sinks superyacht off Sicily

One person was killed and rescuers were searching for six others missing after a superyacht sank during a sudden storm off the coast of Italy's Sicily, officials said.

The boat had 22 people aboard, including 10 crew members, the coast guard said. The majority of those aboard were British, according to Italian media.

Fifteen people were plucked from the water, officials said, including, according to local media reports, a mother and her baby.

"This morning around 5:00 am (0300 GMT), following a violent storm, a 56-metre yacht called Bayesian, flying the British flag, sank near Porticello," the Italian coast guard said in a statement.

Rescuers backed by helicopter who were scouring the waters found one body on Monday, the coast guard said.

"One body was located in the wreck but not yet recovered, at a depth of around 50 metres," a spokesman told AFP.

Earlier, the coast guard said that four Britons, two Americans and one Canadian were missing, it said.

According to media, the yacht was anchored some 700 metres from the Porticello port when it was struck by a waterspout, which roughly resembles a mini tornado over a body of water.

"I was at home when the tornado struck", fisherman Pietro Asciutto told Ansa news agency. "I immediately closed all the windows. Then I saw the boat, it just had one mast, it was really big. I saw it suddenly sink".

A waterspout is a column that descends from a cloud to form a rotating mixture of wind and water over a body of water, according to National Geographic.

The most powerful and destructive type of waterspout is tornadic, which start as true tornadoes, often during severe thunderstorms, according to National Geographic.

- 'No longer there' -

Another witness cited by Ansa said "The boat was all lit up. Around 4:30 am, it was no longer there. A beautiful boat where there was a party. A normal joyous vacation day at sea turned into tragedy".

Media reports said that another boat in the vicinity provided help until rescuers arrived.

Italian authorities have opened a probe into the incident.

The Bayesian was a luxury superyacht built by the Italian shipbuilding firm Perini Navi in 2008.

It had an 11.51-metre mast and could reach speeds of up to 15.5 knots, according to the Boat International website.