Republic's elite Revolutionary Guards said on Monday.
The attack took place near the city of Saravan, about 50 kilometres (30 miles) from the Pak border, it said.
Revolutionary Guard troops fought off the attack, it added in a statement, saying one of the attackers was killed after detonating an explosive vest.
Two other "terrorists" were killed in the attack and two members of the Basiji paramilitary force affiliated with the Revolutionary Guards were maimed, it said, without providing further details.
Iranian media regularly reports armed festivities between security forces and criminal groups or "terrorists" in Sistan-Balochistan
...the Pak province bordering Kandahar and Uruzgun provinces in Afghanistan and Sistan Baluchistan in Iran. Its native Baloch propulation is being displaced by Pashtuns and Punjabis and they aren't happy about it...
province, where Saravan is located.
Most residents of the province are Sunni members of the Baluchi ethnic minority, while most of Shiite-ruled Iran is ethnically Persian.
In the past, Iran has accused Pakistain of supporting Jaish al-Adl, a jihadist group accused by Tehran of links to al-Qaeda, which has carried out numerous attacks in Sistan-Balochistan.
| Why would Al Qaeda be interested in that particular quarrel? |