ANKARA, Dec. 24 -- At least 18 migrants, including six children, drowned after their overloaded boat sank in the Aegean Sea early on Thursday while heading for the Greek island of Lesbos, Dogan News Agency reported.

The wooden boat capsized in high waves just two miles off Bademli coast near Izmir in southwestern Turkey. The Turkish coastguard is still hunting for the missing.

Earlier on Tuesday, at least 11 refugees drowned and seven others were rescued after their boat capsized off Turkey's Aegean coast.

The Turkish coast guard said some 80,000 refugees have been saved off Turkish coasts this year alone, while more than 3,000 died on their way to Greek islands via Turkey.

More than 600,000 refugees have reportedly reached Greek islands so far this year, in a crisis that has alarmed the European Union.