Tunisian rescuers combed the Mediterranean Sea on Thursday for some 200 migrants reported missing after a vessel they were aboard ran into problems in rough waters off the Tunisian coast.

At least 570 people were rescued from the boat off the southern Tunisian port of Sfax. Some have been hospitalized and at least three people died after being taken on shore.

Authorities report the boat got into trouble on Tuesday near the Tunisian island of Kerkennah. The state news agency TAP reported the boat was headed to Italy and carrying people fleeing the war violence in Libya.

Europe has seen a flood of people leaving Libya in recent weeks. The Italian island Lampedusa has been a focal point of refugee landings and is struggling to handle the migration.