Rebels from Jundallah armed group, believed to have links to al-Qaida, have killed four members of the security forces in southeastern Iran near the border with Pakistan, Iran's state news agency said.
IRNA said another 12 border guards were also injured in Monday's attack, part of a low-level insurgency taking place in the country's lawless southeast.
The extremist group are members of Iran's ethnic Baluchi minority, which can also be found in Pakistan and Afghanistan.
The group claims to fight for the rights of Sunni Muslims oppressed by Iran's Shi'ite government.
The group said in a statement posted on its Web site Monday that it had killed 150 members of the elite Revolutionary Guards.