Four British nationals and two Americans are among at least seven people missing after a 180ft yacht sank off the coast of Sicily in the early hours of this morning, with a frantic search now underway.

Fifteen of the 22 people on board, including a one-year-old child and its mother, were rescued after the boat capsized when a tornado hit the area off the coast of Porticello, near Palermo, at around 5am.

Italian media reports that the body of one passenger was found this morning floating alongside the boat, though this has not been confirmed. 

The passengers were mainly British, according to reports, while citizens from New Zealand, Sri Lanka, Ireland, Canada, the US and two dual British and French nationals were also said to be on board.

The group are reported to have been tourists on holiday in Sicily, and it is feared that  those missing may have been trapped inside their cabins.

The vessel has been named as the Bayesian - a luxury yacht which sails under the British flag and has the second tallest mast in the world.

Expert divers have already dived to reach the hull, 49 metres below the water and about half a mile from the coast, according to Italian media.

Nautical maps show the last known location of the Bayesian just after 2am local time, when it was at anchor.

The boat is thought to have arrived in Porticello after a stopping in Milazzo and sailing alongside of Cefalù.

A local Facebook page shared a picture of the yacht at anchor last night, just hours before the high winds hit. 

'That boat was all lit up,' a man in Porticello told the Ansa news agency. 'At around 4.30 in the morning it was gone.  

'A beautiful boat where there had been a party. A normal holiday spent happily at sea turned into a tragedy. 

'The boat was not far from the port. It took very little to raise the anchor and head for the port. Evidently they were surprised by the storm that suddenly hit and they were unable to avoid sinking.' 

The vessel can accomodate 12 passengers and 10 crewmembers.

The only crewmember among the missing is said to be the cook, with those still unaccounted for including British, American and one Canadian citizen, RAI reports.

Coast guards patrol boats and firefighters rescued 15 of those on board this morning, and the survivors will be interviewed by authorities in the coming hours. 

Among them is the boat's captain, who reportedly managed to save himself and is said to be very upset by the incident.

The baby who was rescued was reportedly taken to the Children's Hospital of Palermo, and arrived there with his mother.

Both are said to be fine, with the mother sustaining only minor injuries and the child undergoing tests as a precaution.

The 180ft yacht has a gross tonnage of 473 tons, and was built by the Perini Navi Viareggio shipyard in February 2008 before being refitted in 2020.

The deck area is 436 square metres and the six cabins occupy an area of ​​143 square metres.

It comprises of an aluminum hull, and is powered by two large engines, allowing it to cruise at 12 knots and reach a maximum speed of 15 knots. 

The boat has the second tallest mast in the world and the largest aluminum mast of 75 metres.

Sicily is currently under a weather warning for wind, with video showing strong gusts battering the coast this morning.

CCTV footage from around 4am this morning shows a torrent of wind and rain slamming into Santa Nicolicchia - an area of Porticello where Bayesian was anchored.

The high winds throw umbrellas, plant pots, tables and chairs flying within seconds of hitting, with the local restaurant who shared the footage saying: 'In a moment the hurricane took everything away!'

The owners of Baia Santa Nicolicchia said they were able to open later in the morning once the storm had passed, but added: 'We have no memory of anything like this in our area.'