Evacuated passengers were taken to their original destination

A 45-year-old man and his daughter were reported missing by family members also on the cruise, officials said.

The Greek-flagged Sea Diamond issued a distress signal on Thursday after running aground and taking on water.

Passengers told the BBC the three-hour evacuation proceeded calmly. The ship sank 15 hours after the accident.

"The missing are Jean-Christophe Allain, 45 and his 16-year-old daughter Maud," a merchant marine ministry official told AFP news agency.

Mass evacuation

A flotilla of commercial ships plus six navy helicopters and various navy vessels assisted the rescue.

The remaining passengers were being taken to the port of Piraeus, the ship's original destination.

The Sea Diamond was about one nautical mile (1.8km) off the coast of the island in the eastern Aegean Sea while on a short tour of the Greek islands.

After running aground several hundred metres from shore in Santorini's volcanic lagoon, it was towed off the rocks for the rescue.

Many of the 1,200 passengers are from Germany and the United States, and about 20 are believed to be from the UK, said Louis Cruise Lines, the Cypriot firm which runs the ship. There are also up to 400 crew.

The missing French pair were in a four-berth cabin when the vessel struck a reef. The man's wife and son narrowly managed to escape to the upper decks, the BBC's Malcolm Brabant reports from Athens.

Divers are preparing to examine the wreck, now about 200m down.

American passenger Cliff Jones said: "We were pulling into the port and I think the ship hit a few rocks.

"The ship tilted so far to the right the first five floors were flooded. We just waited at the top to be rescued," he told the BBC.

Greek Tourism Minister Fanny Palli Petralia has said whoever is responsible for the incident will be held accountable in the strictest way.