The clashes, which erupted near the town of Mirjaveh in the province of Sistan-and-Baluchestan while the Iranian forces were patrolling the area, also left three other border guards injured, IRIB News Agency reported.
The so-called Jaish ul-Adl terror group claimed responsibility for the attack in a statement.
Armed bandits, outlaws and drug dealers regularly attack police forces and border guards in southeastern Iran.
Earlier this month, a commander with Iran’s Islamic Revolution Guards Corps (IRGC) was assassinated by two terrorists in Sistan-and-Baluchestan.
Commander Rouhollah Aali was gunned down on April 11 by “two Takfiri terrorists” while traveling to the Kurin District of Zahedan County on duty.
The assailants were subsequently killed by Basij volunteer forces.