A number of Britons were among the passengers who scrambled to safety as a luxury cruise liner ran aground off the Italian coast.
The vessel, which was carrying 4,000 passengers, listed at an angle. According to reports, some passengers jumped into the sea to escape, with one man suffering a fatal heart attack in the water. Three people have been confirmed dead, with the AFP news agency reporting that 70 remain missing.
The cause of the incident is yet unknown, though the press Association are reporting that the ship may have sailed off course. As the sun rose on Saturday, the ship could be seen almost completely on its side.
The Foreign Office said: "We are in close contact with the local authorities and are working urgently to identify British nationals involved.
"A consular team from the British Embassy will shortly be in the area to provide consular assistance."
Pictures of the Costa Concordia record a huge gash more than 150ft long running along the side of the ship towards the stern.
Three bodies have so far been retrieved from the sea. Rescued passengers were taken to the nearby island. The local mayor, Sergio Ortelli, asked for "anyone with a roof" to open their homes to shelter the evacuees.
Elizabeth Nanni, of Isola del Giglio's tourist information, said all passengers had been evacuated from the island to Port Santo Stefano on the mainland. She told BBC News that rescuers "think they have got everyone".
"There was talk at some point that people were trapped inside but I can't confirm that, I have no idea really," she said.
"Luckily the sea was calm and there was no wind which helped a lot yesterday. Of course it always takes some time to organise a rescue in these cases and it was a big shock to everyone.
"The boat was listing and everyone tried to pull together - this island has about 700 residents here so receiving 4,200 was quite a shock, even for us. So we tried to put them in churches and schools and in the tourist office I housed about 100 people in two rooms."
The Foreign Office gave contact details for the British Embassy in Rome for concerned friends and relatives.
The telephone number is (+39) 06 4220 0001, and the Foreign Office in London can be contacted on 0207 008 1500.