While the Kurdish YPG continues to tout the progress they are making against ISIS, the jihadists have managed to get around to carrying out a retaliatory strike of their own, hitting YPG targets east of the city of Raqqa, sparking a long gunbattle and causing a number of casualties.

The exact death toll is a matter of considerable dispute. ISIS claimed 53 YPG were killed, and the Syrian Observatory said a number were killed and injured, but weren’t specific. The YPG insists the ISIS statement was false, but didn’t offer alternative numbers.

The target was a pair of armored personnel carriers and the troops along with them. They were traveling through territory presently held by the YPG, but which was ISIS territory only months ago, taken in the course of the advance on Raqqa.

This is a common strategy for ISIS when they face pressure, carrying out a counter-offensive to try to put the invading force off-balance. Reports of substantial casualties, and even unconfirmed reports ISIS captured some Kurds in this action are likely to succeed in reducing YPG morale.