Turkey's military has returned fire against members of the Kurdish YPG militia in Syria's Afrin region.
At this time it remains unknown as to whether there were any casualties on either side. Turkish officials have said their military retaliated after YPG fighters fired upon their positions. Afrin is in northwest Syria and near the border with Turkey.
The United States supports the Kurdish YPG in the fight against Islamic State. Turkey claims the Syrian Kurdish fighters are terrorists and fears their advance will inflame a Kurdish insurgency.