PARIS — As many as 270 migrants fleeing Libya for Europe may have drowned after their vessel capsized off the coast of Tunisia, the authorities said Thursday.

Rescuers from the Tunisian Coast Guard and Navy were able to save 578 men, women and children from the 100-foot fishing vessel, which was crowded with as many as 850 passengers when it ran aground Tuesday about 30 miles from the Kerkennah Islands, said Col. Lotfi Baili of the coast guard, who helped coordinate the operation.

Hundreds of passengers fell from the vessel when it listed, he said, and others fell into the water during the scramble to reach the military rescue boats. The Tunisians were overwhelmed by the number of migrants who needed to be rescued, he said, and could use only small vessels because the water was so shallow.

Image Credit... The New York Times

The fishing vessel, the Wave, set off from Tripoli, Libya, around noon last Friday, Colonel Baili said, and was carrying migrants from the African nations of Mali, Ghana, Burkina Faso, Ivory Coast and Morocco as well as from Pakistan and Bangladesh.