TEHRAN, Iran — Gunmen killed three members of the Revolutionary Guard in Iran’s southeastern province of Sistan and Baluchistan near the Pakistan border, state media reported.

The Guard members were ambushed while patrolling near the city of Lar in a mountainous area about 1,125 kilometers (700 miles) southeast of the capital Tehran, the official IRNA news agency reported.

IRNA did not report whether any Guard members were injured in the attack.

The Revolutionary Guard is pursing the attackers it calls “terrorists,” but they remain at large. No group has taken responsibility for the attack, IRNA reported.

The province bordering Afghanistan and Pakistan, one of the least developed in Iran, has been the site of occasional deadly clashes involving militant groups, armed drug smugglers and Iranian security forces.

In August, Iran’s security forces killed 13 militants in three separate operations in the province a week after the group killed five policemen who were on patrol.