Divers searching the wreck of a superyacht that sank off Sicily found four bodies Wednesday, as the search continued for two more missing passengers and questions intensified about why the vessel sank so quickly.

Divers and rescue crews unloaded two body bags from the rescue vessels that pulled into port at Porticello. Salvatore Cocina, head of the Sicily civil protection agency, said two other bodies had also been found Wednesday in the wreckage for a total of four.

The discovery indicated that the operation to search the hull on the seabed 50 meters (164 feet) underwater was a recovery, not a rescue, given the amount of time that had passed and no signs of life over three days of searching, maritime experts said.

The Bayesian, a 56-meter (184-foot) British-flagged yacht, went down in a storm early Monday as it was moored about a kilometer (a half-mile) offshore. Civil protection officials said they believed the ship was struck by a tornado over the water, known as a waterspout, and sank quickly.