At least 17 migrants were drowned on Sunday when a boat sank in the Aegean Sea near Turkey.
Those drowned were Syrian migrants who left the Turkish resort town of Bodrum for the Greek island of Kos, Xinhua news agency reported.
The route is considered one of the shortest by sea from Asia to the European Union territory.
Local officials said an eight-metre boat carrying at least 37 people departed from Gumusluk and sank off the Cavusadasi coast on Sunday.
Some 20 migrants have been rescued, and 17 bodies found.
In the first five months of 2015, over 42,000 people, mostly refugees, reached Greece by sea, according to the UN refugee agency UNHCR.
The agency said more than 300,000 people have risked their lives to cross the Mediterranean Sea so far this year, and around 2,500 refugees and migrants have either died or gone missing trying to reach Europe.