At least four die after migrant boat sinks off Greek island of Lesbos

Four migrants died when their boat sank off the Greek island of Lesbos, Greece's coastguard said on Monday, adding seven had been rescued from the sea.

"We recovered four bodies, the rescue operation continues. We don't know if there were more people on the boat," a coastguard official said.

This is the second fatal incident involving migrants off Lesbos, near the Turkish coast, in October.

Greece was on the frontline of a 2015-16 migration crisis when more than a million people fleeing war and poverty in the Middle East and Africa crossed into Europe.

Migrant flows subsequently ebbed. But the country has toughened migration rules, following a resurgence of arrivals from Libya via the islands of Crete and Gavdos.