Greek authorities said 340 people were rescued Friday as a boat carrying a “significant number” of people sank in the Mediterranean Sea off the coast of Greece. Rescuers also recovered four bodies.

Greece sent two patrol boats, a military airplane and three helicopters to international waters, 75 nautical miles south of Crete. Five ships which were passing by also participated in the rescue.

The coast guard told the Associated Press that the boat, measuring up to 25 meters, resembled a large fishing vessel. He added that it sunk within Egypt’s search and rescue area of operation.

“The information we have on the number of people on board the vessel is still unclear — we've heard that there were 400 or 500 people on board, but we cannot confirm that number,” Coast Guard spokesman Nikos Lagadianos said, “There is a huge rescue effort underway”.

A BBC report said improvement in weather conditions has led to an increase in the number of boats with refugees crossing the Mediterranean.

The origin of the ship and its passengers is yet to be revealed, as also where they were headed. Authorities are still scouring the area to locate any potentially missing passengers from the boat.