Forty-one people had been pulled out of the water by Friday evening after a sailboat carrying about 80 migrants overturned northwest of the island of Paros in the Cyclades.
Coast Guard sources said the passengers called the emergency number 112 to say they were in danger at 7.30 p.m. An open sea vessel, four coast guard ships, a Navy helicopter and a C130 aircraft are participating in the ongoing search and rescue operation.
Nine boats nearby are also assisting in the rescue efforts.
This is the third disaster involveving a migrant ship in the Aegean in the last three days.
Overnight and early Friday morning, the coast guard said 90 people ‒ 52 men, 11 women and 27 children ‒ were rescued from a rocky islet some 235 kilometers (145 miles) south of Athens, near the remote island of Antikythera. Eleven migrants have drowned.
At the same time, a separate search operation continued for a third day in the central Aegean Sea, where a boat carrying migrants sank near the island of Folegandros. Thirteen people were rescued, and the survivors reported that at least 17 others were missing. Authorities said the passengers originally were from Iraq.