A large police and coast guard operation is taking place in Greece to find some 200 illegal immigrants.

They are part of a group of 300 that arrived overnight at the island of Evia, north-east of Athens.

More than 100 people - most of them Iraqi Kurds - have already been detained, but the whereabouts of the rest of the group are still unknown.

There have been reports that some of them may have been drowned.

Coast guard ships and helicopters are taking part in the search.

Greece lies on one of the main routes to Europe used by traffickers of illegal immigrants.

From the newsroom of the BBC World Service