ANKARA, Turkey — A fishing boat carrying migrants sank Friday off Turkey’s Black Sea coast, killing at least 21 people and leaving up to five others missing, the Turkish coast guard said.

At least 40 migrants were rescued by coast guard boats and commercial ships, the Coast Guard Command said.

The fishing vessel sank just before dawn off the coast of Kefken, 200 kilometers (125 miles) east of Istanbul, the coast guard said. A coast guard plane and two boats were dispatched after a commercial ship reported a distress signal from a fishing vessel.

The local chief prosecutor’s office said most of the migrants were Iraqis and they were attempting to cross into Romania, a European Union nation. Their vessel’s captain was Syrian and police were searching for their smugglers.

Migrants are increasingly trying to cross the Black Sea from Turkey to reach Romania.

Ambulances and medical teams carried out medical checks. Two injured survivors were immediately rushed to a nearby hospital by helicopter, the state-run Anadolu Agency reported. A pregnant woman miscarried during the tragedy, it added.

Turkish officials say more than 830 migrants were caught at sea along with 10 suspected smugglers while trying to cross the Black Sea in seven separate incidents between Aug. 13 and Sept. 9.