Four Iraqi refugees, including two infants, drowned on Friday when their boat capsized off Turkey's Aegean coast.
The small boat was carrying 13 Pakistani and Iraqi refugees to the Greek island of Kos when it sank off the Aegean resort town of Bodrum, Xinhua quoted state-run Dogan news agency as saying.
Turkish coast guards rescued eight refugees, while operations to find a missing one were still underway.
A Turkish man suspected of organising the trip was detained.
Turkish coast guards have held around 500 so-called "hope mongers" who were carrying out smuggling activities in Turkey during the last five years.
Some 80,000 refugees have been rescued off Turkish coasts this year alone, while more than 3,000 died on their way to Greek islands via Turkey.
Over 600,000 refugees have reportedly reached Greek islands so far this year, in a crisis that has alarmed the European Union.