A fishing boat carrying migrants sank on September 22 off Turkey's Black Sea coast, killing at least 21 people and leaving up to five others missing, the Turkish coastguard said.
At least 40 people were rescued by coastguard boats and commercial ships, the Turkish Coastguard Command said.
According to the coastguard, the fishing vessel sank just before dawn off the coast of Kefken, 200 kilometers east of Istanbul.
Local authorities 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.
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 August 13 and September 9, Turkish officials said.