About 340 migrants have been rescued and four bodies have been pulled from the sea after a boat capsized in the Mediterranean Sea, Greek officials say.

Others are thought to be missing from the boat which was found in international waters, 75 nautical miles south of the Greek island of Crete.

Ships, helicopters and planes are engaged in the rescue operation.

In a separate incident, "more than 100 bodies" were recovered off the coast of Libya, the AP news agency said.

The local head of the International Organisation for Migration Daniel Esdras told the BBC that the capsized vessel off Crete was a 25-metre boat that can typically carry at least 700 people.

Officials have said they believe the boat "left from Africa" though it is still not clear from where.

Most of the survivors were put on board a cargo vessel heading to Italy. Others were taken to Egypt, Turkey and Malta, a spokesperson for the Greek coastguard said.

Meanwhile, the number of dead from the boat that sank off Libya's coastline has reached 107, Libyan Red Crescent spokesman Mohammed al-Mosrati said, quoted by AP.

They included 40 women and five children and are thought to have died in the past 48 hours, Mr al-Mosrati said.

They were washed up on a beach near the city of Zuwara, from which many unseaworthy boats are believed to have set out for Italy packed with migrants.

New route?

The UN said this week that more than 2,500 people had died in 2016 trying to make the journey towards Western Europe.

A recent improvement in weather conditions has led to an upsurge in the numbers of boats crossing the Mediterranean.

This marks the second time this week that migrants have had to be rescued in waters off the Greek coast. Up until now few migrants have landed on Crete, which lies north of Libya and Egypt.

Friday's incident is likely to deepen concerns about a new smuggling route, one that could bring more tragedies at sea, following the closure of the Balkan route from Greece to Turkey in March.