A Greek navy frigate was towing a crippled freighter with hundreds of migrants on board through gale-force winds and high waves to safety on the southern island of Crete on Wednesday, a day after it suffered engine failure in international waters.

The 77-meter (250-foot) Baris cargo ship carrying some 700 people trying to enter Europe was being towed at a speed of about 3.4 miles per hour toward the port town of Ierapetra in southern Crete. It is expected to arrive late Wednesday.

The coast guard said initial indications suggested passengers included Syrians and Afghans heading for Italy. It was unclear where, and exactly when, the Kiribati-flagged ship had set sail from.

The ship is one of the largest boatloads of migrants trying to cross into Europe across the Mediterranean this year. Tens of thousands of people seek to enter Europe illegally every year, paying smuggling gangs to ferry them across the Mediterranean. Hundreds have died each year in the attempt.

With the proximity of its eastern Aegean Sea islands to the Turkish coast, Greece has been a popular route for migrants, many of whom are trying to make their way to western and northern European countries. Greece and Italy have borne the brunt of recent waves of migrants and refugees, most fleeing the war and violence in Syria and Libya.

Greek authorities said the vessel ran into engine trouble Tuesday about 30 nautical miles off the southeastern tip of Crete. Four merchant ships, the Greek navy frigate Hydra and an air force rescue helicopter were dispatched to evacuate the vessel if necessary.

Coast guard spokesman Nikos Lagadianos said later Tuesday that there were no reports of health problems but anyone needing medical attention would be airlifted to hospital.

Just days before the freighter ran into trouble, 228 men, women and children were rescued from a crippled ship off Cyprus in the eastern Mediterranean. They told officials they were Syrian refugees who were hoping to reach Italy. More than 150,000 migrants have arrived this year in Italy.

EU regulations stipulate refugees seeking asylum must apply in the first EU country they arrive at.