At least four dead as migrant boat sinks off Greece

At least four migrants died after their boat was grounded on an islet north of the Greek island of Antikythera on Thursday, the Greek coastguard said.

Some 90 migrants are currently stranded on the islet but cannot be evacuated before early Friday because of poor weather conditions, state television said.

Several coast guard vessels have been deployed in a search and rescue operation.

Thursday's shipwreck came the day after a dinghy carrying migrants capsized off the island of Folegandros, killing at least three people.

Thirteen people were rescued, while dozens remain missing, Greek authorities said.

Survivors gave conflicting accounts, some telling authorities there were originally 32 people aboard, while others put the number at around 50, a coastguard official told AFP.

The UN refugee agency UNHCR said the Folegandros shipwreck was the worst in the Aegean Sea this year.

"This shipwreck is a painful reminder that people continue to embark on perilous voyages in search of safety," said Adriano Silvestri, the UNHCR's assistant representative in Greece.

The UNHCR estimates that more than 2,500 people have died or gone missing at sea in their attempt to reach Europe from January through November this year.

Nearly one million people, mainly Syrian refugees, arrived in the EU in 2015 after crossing to Greek islands close to Turkey.