ANKARA (Reuters) - Fifteen people drowned when a fishing boat carrying migrants sank off the Turkish coast in the Marmara Sea on Friday and up to 15 more were missing, Turkey's coast guard said.
The boat sank off the northwestern province of Kocaeli shortly after calling for help, the coast guard said in a statement. Forty migrants were rescued from the sea so far and teams were still searching for another 13 to 15 people, it said.
The search effort included two helicopters, as well as planes and commercial boats.
The state-run Anadolu news agency said the rescued migrants were brought back to Kocaeli, where they were treated at a make-shift hospital at the dock. It said two of the injured were transferred to a hospital in the city.
Their origin and destination were not immediately clear.
Turkey agreed with the European Union to help curb a flood of illegal migrants - many of them passing through Turkey or its waters - on the way to Europe. While that has helped significantly reduce the illegal flow to Europe, some migrants still risk their lives trying to make the perilous voyage.
But there are fears that deteriorating relations between Europe and Turkey could endanger the deal, under which Ankara is supposed to receive 3 billion euros in financial aid and visa-free travel for Turks to Europe.
Turkey says the European Union has yet to fulfil its end of the bargain and has warned it could re-evaluate or suspend all of the agreement.
(Reporting by Gulsen Solaker and Tuvan Gumrukcu; Editing by David Dolan and Ralph Boulton)