Greece migrant boat disaster: Survivors 'swam for hours surrounded by children's bodies'

Some of the stories now emerging from the boat disaster off Greece on Wednesday morning create a picture of unthinkably horrific conditions onboard.

Up to 500 people are missing after an overcrowded fishing boat carrying migrants capsized in the Mediterranean Sea, the United Nations has said.

Authorities rescued 104 people and recovered 78 bodies in the immediate aftermath of the tragedy, but nothing has been found since.

Witness accounts suggested 400-700 people had packed the 20-30m-long trawler, which capsized and sank about 50 miles from the southern coastal town of Pylos as it was travelling from Libya to Italy.

A Greek social worker, who looked after some of the survivors, told us she had heard that water ran out on the boat days before it sank, forcing passengers to drink their own urine and suck water from the melting refrigerators.

Many of them are suffering severe mental trauma.

She recalled one survivor who told her that "for two hours he was swimming surrounded by the bodies of children" and a young man in his 20s who "wanted to commit suicide, wanted to jump into the sea and kill himself because he couldn't take it anymore".

The survivors have been moved to an immigration centre in central Greece.

The warehouse where they were staying is now being cleaned and the aid agencies have left. It's clear they're not expecting any more survivors.

The media attention has shifted to the Hellenic Coastguard office in the port of Kalamata as questions are now arising over whether they could have done more to avert the disaster.

One Greek newspaper quoted an anonymous source claiming that a rope had been attached to the boat around three hours before it capsized.

There are also questions about why nothing was done to rescue at least some of the passengers when it was obvious the boat was dangerously overcrowded, with migrants onboard and therefore almost certainly people smugglers too.

The coastguard has previously said it acted in accordance with international law because the boat was in international waters.

Nine Egyptian men, aged 20 to 40, have been arrested on allegations of people smuggling and participating in a criminal enterprise.