At least 270 migrants from Libya heading towards Europe may have drowned after their ship sank off the coast of Tunisia in a storm, authorities said on Thursday.

About 578 men, women, and children were saved by rescuers from the Tunisian Coast Guard and Navy. The 100-foot fishing vessel was crowded with as many as 850 passengers when it ran aground Tuesday about 30 miles from the Kerkennah Isles, said Colonel Lotfi Baili of the Coast Guard, the New York Times reported.

Baili said that hundreds of passengers fell from the vessel when it listed, while others fell into the water scrambling to reach the military rescue boats.

He further added that the fishing vessel, the Wave, set off from Tripoli, Libya, around noon last Friday. It was carrying migrants from different countries like Mali, Ghana, Burkina Faso, Ivory Coast, Morocco, and even from Pakistan and Bangladesh.

Survivors were taken to the Choucha refugee camp on the Tunisian-Libyan border. While 7 injured survivors were sent to the emergency department at the University Hospital Habib Bourguiba in Sfax, 2 pregnant women were transfered to the maternity ward, an AP report said.