Liner Sinks; All but 15 of 580 Aboard Rescued : Sea drama: Massive operation off South Africa mobilizes ships and helicopters. Bomb threat is reported.

The Greek passenger liner Oceanos sank in storm-lashed seas 1 1/2 miles off South Africa’s “wild coast” Sunday, but rescuers said all but 15 of the 580 passengers and crew members are accounted for.

In Cape Town, police said harbor authorities received a bomb threat against the Oceanos shortly before the ship sailed for Durban on Friday evening, about 24 hours before the vessel began to take on water. The caller reportedly said the bomb had been smuggled aboard in a wedding cake.

But a search by the crew found no explosive device.

By nightfall Sunday, most of those aboard the liner were safe after a massive rescue operation employing ships and helicopters.

Hopes were still high that the remaining 15 had been picked up by two vessels seen near the wreck off the Transkei homeland village of Coffee Bay, about 80 miles northeast of the Indian Ocean port of East London.

A special team was appointed to investigate the bomb threat, police said.

A national police spokesman said harbor authorities in East London received the threat by phone shortly before the ship sailed for Durban, but the Greek captain reportedly refused to let police on board to investigate.

The Oceanos issued a distress message late Saturday, saying its engine room was flooded and that it had lost power, but the captain, Yiannis Avranas, could not tell reporters the cause of the mishap.

He said Sunday at the rescue center in Coffee Bay that the ship’s engine room flooded after the liner sprang a leak.

“We tried all night to get people off. (The rescuers) came late,” Avranas said.

The 39-year-old liner, which was bound for an Indian Ocean cruise after picking up passengers in Durban, sank shortly after the last known passengers had been lifted off by rescue helicopters.

Military officials said they did not know why the ship began taking on water but that its proximity to shore suggested it may have hit a large rock or a reef off the notoriously dangerous coast.

The ship foundered because of the flooded engine room and began listing heavily after it was battered by waves up to 24 feet high and winds gusting up to 88 miles per hour.

Some passengers expressed anger at the way the crew responded when the ship began taking on water.

“The lights went out. No one knew what was going on,” said passenger John Hinklin. “The next thing we know, the . . . lifeboat left with the crew on it.”

“They didn’t tell us anything,” passenger Tessa King said of the crew. However, military officials said many crew members remained on board until near the end.

Passenger Graham Kingsley-Wilkins and his wife, Hester, were among those rescued by helicopter. She said there “were not enough lifeboats and the swells were too big for (other ships) to get close.”

Terrified passengers said they lined the ship’s upper deck all night, waiting for help to arrive. As the ship began to list, some leaped overboard, according to South African air force Maj. Gerrie Evert.

“People just jumped into the sea when the ship started to go over,” he said.

At least 15 military helicopters airlifted more than 200 people off the Oceanos, Evert said, and more than 300 were pulled from the sea or from life rafts.

Planes dropped life preservers to people in the water, he added. Many were saved by three merchant ships, including an oil tanker, that rushed to the scene.

Air force Maj. Andres Steenkamp said searchers followed the current south and found a man in a life vest eight miles from the ship; he had been in the water 10 hours. A helicopter airlifted him to safety, Steenkamp said.

Air force planes and helicopters circled the sunken ship until nightfall Sunday to see if anyone was still in the water. A search by navy divers did not turn up anyone, officials said.

The 7,554-ton Oceanos--495 feet long and 64 feet wide--was carrying mostly South African passengers, with a crew of Britons, Greeks, Egyptians, Hungarians and Mauritians.

The ship had left the Indian Ocean port of East London on Saturday on the return leg of a Durban-Cape Town-Durban cruise.