Iran's Islamic Revolutionary Guards Corps (IRGC) says four security forces have been killed in the southeastern province of Sistan and Baluchistan, where intense anti-government protests have rocked the region in recent months.
The IRGC said in a statement on December 19 that the four killed were part of the 44th Qamar Bani Hashem Brigade of the IRGC Ground Force. One was an IRGC member, while the three others were part of its Basiji paramilitary force.
It blamed "terrorist groups" for the killings, a term it often uses to describe groups opposed to the government.
No details of what happened were released, nor did the IRGC identify the actual group it says carried out the attack.
Iranian security forces in Sistan-Baluchistan have been targeted repeatedly by Sunni militants thought to be crossing into the region from Pakistan and Afghanistan. Security forces also frequently clash with drug traffickers in the province.
Sisten-Baluchistan has been a hotbed of unrest since the September 16 death of 22-year-old Mahsa Amini while in police custody for an alleged violation of Iran's rules that require women to wear head scarves in public.
Exacerbating the tensions, a police commander in the city of Zahedan in Sistan-Baluchistan is alleged to have raped a 15-year-old protester.
The Iranian government has unleashed a brutal crackdown over the unrest -- one of the deepest challenges to the Islamic regime since the revolution in 1979.
Sunni Muslims make up the majority of the population in Sistan-Baluchistan but account for only about 10 percent of the population in Shi'a-dominated Iran overall.
Since Amini's death, almost 500 people have been killed in the police crackdown, according to rights groups. Several thousand more have been arrested, including many protesters, as well as journalists, lawyers, activists, digital rights defenders, and others.