Three babies were amongst the six people who died after their boat capsized off the coast of western Turkey.
Nine people were rescued by the coast guard overnight on Saturday, while search and rescue efforts are continuing for one missing person after the incident off the coastal province of Ayvalik.
The boat was believed to be en route to Greece's Lesbos island which is only 12 miles away from the Turkish coast.
From January to July this year at least 54 "irregular migrants" died trying to cross to Europe from Turkey, according to coast guard statistics.
Between January to April this year, 370 migrants died on the Libya-Italy route.
District governor Gokhan Gorguluarslan said the people who were trying to cross to the Greek island were Turkish citizens. Two of them are believed to be involved with the smuggling operation, affiliated to the proscribed Gulen movement (FETO), added Mr Gorguluarslan.
FETO is accused by the Erdogan government of orchestrating the defeated coup of July 2016. However, FETO denies direct culpability.
It also says FETO is behind a long-running campaign to overthrow the state through the infiltration of Turkish institutions like the military, police and judiciary.
Since the July 2016 coup, thousands of people have fled Turkey to escape the government's crackdown on FETO sympathisers.
Many have had to flee illegally because the government has taken away their passports, say human rights advocacy group Amnesty International.
Additional reporting by Reuters
