Eight children were among the 11 migrants who drowned when their boat sank off Turkey’s western coast, state media report.
Eight other people were rescued from the waters off Cesme, a tourist resort on the Aegean coast opposite the Greek island of Chios.
Their nationalities are not yet known.
Turkey has been a key transit point for migrants trying to reach Europe, mainly via Greece. Many are fleeing violence and persecution in their countries.
Many rely on people smugglers and face dangerous land and sea routes which often result in deaths. In 2016, Turkey reached a financial deal with the European Union to stem the flow of migrants and refugees to Europe.
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The Turkish Coast Guard said it responded to “screaming sounds” from the sea at around 20:30 local time (17:30 GMT) on Saturday.
Cesme is just 15km (nine miles) from Chios, where thousands of migrants are living in overcrowded and unsanitary conditions.