A large search operation was launched following the night-time incident some 45 miles (75km) south-west of the Peloponnese region.
A fishing boat carrying dozens of migrants capsized and sank off the southern coast of Greece early on Wednesday, killing at least 32 people.
A large search and rescue operation was launched following the night-time incident some 45 miles (75km) south-west of the Peloponnese region.
Authorities said 104 people have been rescued so far, including four who were taken to hospital with symptoms of hypothermia.
It was unclear how many passengers remained missing at sea after the 32 bodies were recovered, the Greek coast guard said.
Six coast guard vessels, a navy frigate, a military transport plane, an air force helicopter, several private vessels and a drone from the European Union border protection agency Frontex were taking part in the ongoing search.
The Italy-bound boat is believed to have sailed from the Tobruk area in eastern Libya.
The Italian coast guard first alerted Greek authorities and Frontex about the approaching vessel on Tuesday.
Smugglers are increasingly taking larger boats into international waters off the Greek mainland to try to avoid local coast guard patrols.
On Sunday, 90 migrants on a US-flagged yacht were rescued in the area after they made a distress call.
Separately on Wednesday, a yacht with more than 70 migrants on board was towed to a port on the south coast of Greece’s island of Crete after authorities received a distress call.
