TEHRAN : Iranian security forces have killed in a fresh clash four members of an extremist rebel group behind an attack that left 14 Iranian border guards dead, a top border guard commander said Tuesday.

"We clashed with Jaish-ul Adl and killed four of them," the Fars news agency quoted brigadier general Hossein Zolfaqari, commander of Iran's border guards, as saying. He did not say when or where the new clash took place.

Jaish-ul Adl, a Sunni rebel group formed last year whose name means Army of Justice in Arabic, has claimed responsibility for the deadly ambush on Friday in the mountains of Sistan-Baluchestan in the restive southeast. The attack killed 14 border guards and wounded another seven. Iran in retaliation said it had executed 16 "rebels" -- eight Sunni insurgents and eight drug traffickers, all of whom had been on death row, according to Iranian media. "Whatever measure they take against us, our response will be more crushing," Zolfaqari said.

In a press briefing in the afternoon, he said that 20 "bandits" had been killed in 67 clashes near the border since March 2013, the Mehr news agency reported.

The general also warned that Iran "reserves the right to pursue the bandits on Pakistani soil," adding that his unit had informed its Pakistani counterparts of this, Mehr added.

Tehran has demanded Islamabad take "measures to control the borders more seriously," saying the militants had crossed from Pakistan and fled back across the border after the attack.

Iran says it plans to exert more pressure on Pakistan to prevent such attacks.

"A deputy interior minister will visit Pakistan to discuss the attack," foreign ministry spokeswoman Marzieh Afkham said Tuesday during her weekly briefing.

Another Sunni militant group, Jundallah, Arabic for Soldiers of God, has also launched deadly attacks on civilians and officials in the southeast.

Iran captured and hanged its leader, Abdolmalek Rigi, in June 2010.

The restive region near the Pakistani border is home to a large community of minority Sunni Muslims, unlike the rest of Shiite-dominated Iran.

Drug traffickers and Sunni militants have clashed with Iranian forces in the region on several occasions.