ZEEBRUGGE, Belgium--A ferry bound for Britain with 543 people aboard capsized last night in an accident that sent icy water rushing through the decks and trapped more than 200 people in darkness with little hope of survival, officials said.

Twenty people were confirmed dead, 97 injured and 202 saved by small crafts, nearby freighters, helicopter winches and other available means of rescue, according to Olivier Vanneste, governor of West Flanders province.

He said 224 people were missing.

"There was little hope," for those unaccounted for and believed trapped inside the 7,951-ton, British-owned Herald of Free Enterprise, Belgian Transport Minister Herman de Cross told reporters more than seven hours after the accident.

"We are faced with a tragic accident, this is a real catastrophe," said Prime Minister Wilfried Martens, who went to the scene along with King Baudouin and Queen Fabiola.

The British coast guard at Dover, England, the ferry's destination 85 miles away, said earlier that at least 26 people were known dead and that there were approximately 300 survivors. The later information from Belgian government authorities upped the toll of the missing and presumed dead.

The rescued were taken to three nearby hospitals, and those not needing immediate attention were given first aid, coffee and blankets at waiting stations at the harbor.

Some 20 divers worked into the night, with search lights blazing, looking for survivors. The ship was lying on a sandy bed a half-mile outside this North Sea harbor, with about one-fourth of it above water as the tide receded.

Helicopters hovering overhead dropped rescue workers to grab survivors, many of them wearing orange life vests, and haul them to safety.

"Divers told us they have seen...a great number of victims inside the ship," Vanneste said.

Raymond Nossent, a spokesman for Townsend Thoresen, the ferry's owners, said divers were still finding survivors in air pockets inside the ship more than six hours after the accident.

There were conflicting reports on just how the accident occurred. It happened at 7:50 p.m. just after the ferry, loaded with people and vehicles, pulled out of the harbor for what would be a 4 -hour sail. Seas were calm near the harbor.

Belgian television, quoting the Zeebrugge port authority, said the ferry's cargo doors had not closed properly, letting water into the hold containing cars and trucks.

A Dover coast guard spokesman said the ferry hit the harbor's east pier, while the Martime Rescue Cordination Center at Plymouth, England, said it struck the harbor wall.