Turkey's coast guard says seven Afghan nationals died, including three children, while trying to cross into Greece, but that it managed to rescue 13 people from the sinking boat.

In a statement Tuesday, it said a rescue ship and helicopter were dispatched late Monday near the western province of Canakkale following a tip. A half-sunk 6-meter fiber boat was found.

The coast guard said it rescued 12 Afghans and one alleged Iranian smuggler.

Turkey and the European Union signed a deal in 2016 to curb illegal migration.

Official figures show that in 2017 Turkey stopped some 45,000 Afghan nationals and a further 42,000 so far this year from reaching Greece.

Afghan migrants are second only to Syrians in attempted crossings from Turkey.