At least five migrants drowned after their wooden boat capsized off Greece's southern island of Gavdos, the coastguard said on Saturday, and witnesses said many were still missing as search operations continued.
So far 39 men - most of them from Pakistan - have been rescued by cargo vessels sailing in the area. They have been transferred to the island of Crete, the coastguard said, adding that the number of those missing had not yet been confirmed.
Coastguard boats, merchant vessels, an Italian frigate and naval aircraft have been searching the area since Greek authorities were alerted about the incident on Friday night.
In separate incidents on Saturday, a Malta-flagged cargo vessel rescued 47 migrants from a boat sailing about 40 nautical miles off Gavdos, while a tanker rescued another 88 migrants some 28 nautical miles off the tiny island in Greece's south.
According to initial information, coastguard officials believe the boats left together from Libya.
Greece was a favoured gateway to the European Union for migrants and refugees from the Middle East, Africa and Asia in 2015-2016, when nearly 1 million people landed on its islands, mostly via inflatable dinghies.
Incidents with migrant boats and shipwrecks off Crete and its tiny neighbour Gavdos, which are relatively isolated in the central Mediterranean, have increased over the past year.
In 2023, hundreds of migrants drowned when an overcrowded vessel capsized and sank in international waters off the southwestern Greek coastal town of Pylos. It was one of the deadliest boat disasters ever in the Mediterranean Sea.