The source, speaking on condition of anonymity due to security concerns, said a Turkish base used to train Sunni Arab and Kurdish Peshmerga fighters came under attack from anti-tank weapons at around 4.15 p.m. local time (1315GMT).
An M-60 tank based at Bashiqa Camp, to the northeast of Mosul, was slightly damaged in the attack. Turkish forces returned fire towards the building where the firing had come from.
Eight shells destroyed the building, killing 10 terrorists, the source said. The remaining terrorists were killed as they tried to flee the area by vehicle.
There were no casualties within the camp.
It was the third attack on the camp by Daesh. Turkey reinforced the base in December.