ISTANBUL, Jan. 15 (Xinhua) -- A four-year-old girl drowned on Tuesday when a boat carrying migrants to a Greek island sank off Turkey's Aegean coast.

The inflatable boat began to leak near the resort town of Kusadasi in the southwestern province of Aydin, the NTV broadcaster said.

The Turkish coast guard rescued a total of 40 migrants, NTV said, adding the search was continuing in the sea as it was not immediately clear how many people were on the boat.

A total of 398 migrants have attempted to reach Greek islands via Turkey in the first 15 days of this year, according to figures released by the Turkish coast guard.

A total of 26,678 migrants on their way to Europe were blocked off Turkey in 2018, up from 21,937 in 2017, with the Aegean Sea remaining the favorite route, the data showed.

Turkey signed a deal in March 2016 with the European Union to help reduce the flow of illegal immigration.