A Kurdish Peshmerga stands at a frontline position overlooking areas held by ISIS in 2015. Photo: Seth J. Frantzman.

Iranian forces launched an artillery barrage on armed rebels in a northwestern border area on Saturday, a day after three Iranian border guards were killed in the remote region where the borders of Iran, Iraq, and Turkey meet, Iranian state media reported.

The Revolutionary Guards said its ground forces targeted positions of “counter-revolutionary terrorist groups on the other side of the northwestern borders of our country,” inflicting heavy losses and casualties, Iran’s state news agency IRNA reported.

Clashes with Iranian Kurdish militant groups are common in the area and Iran occasionally shells northern Iraq, where it says rebel fighters take shelter.