An attack by armed separatists on a police station in a southeastern city killed 19 people, including four members of Iran’s elite Islamic Revolutionary Guard, Iran’s state-run Irna news agency reported on Saturday.

The assailants in Friday’s attack hid among worshippers near a mosque in the city of Zahedan and attacked the nearby police station, according to the report.

Irna quoted Hossein Modaresi, the provincial governor, as saying 19 people were killed. The outlet said 32 Guard members, including volunteer Basiji forces, were also wounded in the clashes.

It was not immediately clear if the attack was related to nationwide anti-government protests gripping Iran after the death in police custody of a young Iranian woman.

Sistan and Baluchestan province borders Afghanistan and Pakistan and has seen previous attacks on security forces.