Kurdish fighters say recent Turkish airstrikes have killed at least 11 people across Kurdish-controlled parts of northeastern Syria, with five civilians among the dead. Turkey has intensified cross-border raids since Sunday, when a pair of attackers detonated a bomb outside government buildings in Ankara. Turkey blamed the attack on the outlawed Kurdistan Workers’ Party and the closely affiliated Kurdish YPG militia, which is allied with the U.S. in its fight against ISIS.

On Thursday, the Pentagon said one of its F-16 fighter jets shot down an armed Turkish military drone as it approached U.S. forces in Syria and ignored commands to change course. It was an unprecedented direct military exchange between Turkey and the U.S. — two NATO allies.