DUBAI: Four members of Iran’s Revolutionary Guards were killed in the country’s southeast and the killers fled to neighboring Pakistan after coming under fire, the official IRNA news agency reported on Monday.

IRNA gave no further details about the incident in the Saravan area of Sistan-Baluchistan province, scene of some of the deadliest unrest during Iran’s nationwide protests, and a region where security forces clash often with drug smugglers.

Citing a Revolutionary Guards statement, IRNA said three of the dead were members of the Basij, a militia affiliated with the Revolutionary Guards that has been widely deployed during a state crackdown against protesters.

“The perpetrators of attack ... fled to Pakistan after receiving heavy fire,” IRNA reported, citing a statement issued by the Guards.

The impoverished Sistan-Baluchistan province is home to the Baloch minority that has long complained of discrimination by authorities.

The provincial capital, Zahedan, was scene of some of the deadliest unrest during the wave of nationwide protests ignited by Mahsa Amini’s death in morality police custody, when security forces killed at least 66 people in a crackdown on Sept. 30, according to Amnesty International.

The unrest, in which demonstrators from all walks of life have called for the fall of Iran’s ruling theocracy, has posed one of the biggest challenges to the Islamic Republic since its 1979 revolution.

A Baloch militant group, Jaish al Adl, has previously mounted attacks on Iranian security forces in the area. Iranian authorities say the group operates from safe havens in Pakistan, which Islamabad denies. 

According to activist HRANA news agency, 502 protesters and 62 members of security forces had been killed as of December 18 during the unrest ignited by Amini’s death.