4 Dead, Hundreds Rescued From Capsized Migrant Boat in the Mediterranean Sea

Greek officials sent two patrol boats and two helicopters to the area.

— -- Four bodies were recovered and 342 people were rescued today from a sinking migrant boat carrying hundreds of refugees in the Mediterranean Sea, according to the Organization for Migration, which estimates there could be around 700 on board.

The vessel resembled a large fishing boat that had been carrying a "significant number" of people when it was located roughly 75 miles south of Crete island, the Greek Coast Guard said.

Five commercial ships, two Coast Guard vessels and a Greek Air Force plane were helping in the rescue effort.

The operation was continuing to locate any potentially missing passengers from the migrant boat, officials said.

It's unclear where the boat's passengers were from, where the boat had set off from, or where it was heading.

ABC News' Dada Jovanovic contributed to this report.

This is a breaking news story. Check back for updates.