Two dead after migrant boat sinks off Turkey coast
Seventeen others were rescued after the boat ran into trouble 50 metres off the coast of Bodrum district in Mugla province, it said in a statement.
Initially 20 people were taken to hospital including three who managed to reach the shore without assistance, but two later died.
Search and rescue efforts were continuing, the coastguard said. The boat, believed to be carrying nearly 30 people, had been on its way to the Greek island of Kos, NTV reported.
Officials did not give details of the migrants' nationalities, although Turkey hosts over three million Syrian refugees and up to 300,000 Iraqis.
Earlier this month, twenty-two people, including children, died when a vehicle carrying migrants reportedly heading for EU member Greece plunged off the highway into a waterway in western Turkey.
The vehicle was travelling on a highway near Izmir airport when it flipped over and fell into the channel several metres below, state-run Anadolu news agency said.
The nationality of the migrants was not immediately clear, but 22 people died in the crash and another 13 others were hurt, the agency said, hiking an earlier toll of 19 dead.
Turkish television pictures showed the wreckage of the vehicle upside-down in the river channel, reduced to burned-out metal by the impact of the crash with corpses strewn alongside it.
Rescue workers later used a crane to lift it on to the road, with images showing the vehicle's back end was simply an open container into which the migrants had been crammed.
Among the dead were two babies, two children and a pregnant woman, it said.
The number of migrants coming to Europe has declined since the influx hit a peak in 2015 when more than a million people landed in Greece from Turkey, mainly via boats.
Turkey and the European Union agreed a deal in 2016 to stem the flow of migrants, with Ankara agreeing to take back migrants landing on Greek islands in exchange for incentives including financial aid.
Key transit point
Turkey is a key transit point for migrants from troubled countries in the Middle East, Asia and Africa seeking a new life in Europe.
A million migrants crossed from Turkey into Greece in 2015, mostly by boats, in a crisis which forced a deal between Ankara and the EU to stem the flow of people.
Numbers have fallen since but people are still undertaking what is a highly perilous journey and the flow has ticked up this year from 2017.
According to UN figures, more than 24,500 migrants have arrived in Greece by sea so far this year, with 118 people losing their lives via this route.