A man has died, and six people are missing after a luxury yacht encountered an unexpectedly violent storm and sank off the Sicilian capital, Palermo, on Monday, the Italian coast guard said.

The 56-meter-long sailboat was identified as the British-registered Bayesian and sank with 22 people aboard shortly before sunrise, the coast guard said in a statement.

The missing people were of British, American and Canadian nationality, the coast guard said. Fifteen people have been rescued so far, including a one-year-old child.

According to a Reuters report, British tech tycoon Mike Lynch is among those unaccounted for.

The coast guard said the boat had been found at a depth of 49 meters and that divers are inspecting the wreck. The Bayesian was built by Italian shipbuilder Perini in 2008 and was last refitted in 2020. Yachting company Camper & Nicholsons is said to be managing the craft.

The boat left the Sicilian port of Milazzo on August 14 and was last tracked east of Palermo on Sunday evening, with a navigation status of "at anchor," according to vessel tracking app Vesselfinder.

A UK foreign ministry spokesperson said British officials were in contact with local authorities over the incident and are ready to provide consular support for Britons who were affected.

(With input from Reuters)