Five migrants, including a baby, hoping to reach Europe via Greece drowned when their speedboat capsized off the Turkish coast, Dogan News Agency said on Thursday.
The Turkish Coast Guard rescued nine people after they called for help late on Wednesday and recovered five bodies, it said. The group, comprised of Afghans and Iranians, were trying to reach the Greek island of Lesvos in the Aegean Sea.
The European Union has offered Turkey billions of euros in aid to curb illegal migration.
Under a draft deal struck on Monday, Turkey agreed to take back all irregular migrants in exchange for more funding, faster visa liberalisation for Turks, and a speeding up of Ankara's long-stalled EU membership talks.
The aim is to discourage illegal migrants and break the grip of human smugglers who have sent them on perilous journeys across the Aegean. But migrants have continued to try to cross from Turkey's coast in recent days.
More than 130,000 people this year have reached Europe from Turkey, which borders Iran and conflict zones in Syria and Iraq, while 350 people have died on the perilous journey, according to the International Organisation for Migration.
More than 35,000 people are trapped at the Greek-FYROM border at Idomeni as Europe tries to close the Balkan route to foreigners fleeing violence and economic upheaval.