Several wounded in clashes in restive Sistan-Baluchestan province which borders Afghanistan and Pakistan.
At least 11 Iranian security force members have been killed in an attack on an Islamic Revolutionary Guard Corps (IRGC) headquarters in the southeastern border province of Sistan-Baluchestan, state media reported.
In the ensuing overnight clashes with security forces, 16 members of Jaish al-Adl (Army of Justice) – a Sunni armed group – were killed, Iranian state TV reported on Thursday.
The attack took place in the towns of Chabahar and Rask in Sistan-Baluchestan which borders Afghanistan and Pakistan.
Reporting from Tehran, Al Jazeera’s Dorsa Jabbari said it was one of the deadliest attacks carried out by Jaish al-Adl.
“Gunmen stormed various security and military compounds simultaneously … and they also had suicide vests on,” Jabbari said, adding that the fighting continued for several hours.
“The terrorists failed to succeed in achieving their goal of seizing the Guards headquarters in Chabahar and Rask,” Deputy Interior Minister Majid Mirahmadi told state TV.
Ten security officers were injured in the fighting in the impoverished region, which has a predominantly Sunni Muslim population.
Jabbari said the attack took place at a very “critical time” for Iran, coming days after its consulate in Damascus, Syria, was hit in a suspected Israeli missile strike for which Iran pledged revenge.
Brigadier-General Mohammad Reza Zahedi, a senior commander in the IRGC’s Quds Force, and his deputy, General Mohammad Hadi Hajriahimi, were killed in Monday’s attack.
“Many questions will be asked about how this attack was able to be carried out at this time,” Jabbari said.
Jaish al-Adl was formed in 2012 and is blacklisted by Iran as a “terror” group.
The group claimed responsibility for an attack in December that killed 11 officers, one of the deadliest assaults in years, at a police station in Sistan-Baluchestan’s city of Rask, about 1,400km (875 miles) southwest of the capital, Tehran.
It also said it was behind a strike on a police station in Rask that killed one officer on January 10.
Later that month, Iran struck two bases of the group in Pakistan with missiles, prompting a rapid military riposte from Islamabad targeting what it said were separatist armed rebels in Iran.
Jaish al-Adl says it seeks greater rights and better living conditions for ethnic minority Baluchis in Shia-dominated Iran. It has claimed responsibility for several attacks in recent years on Iranian security forces in Sistan-Baluchestan.
The area has long been plagued by unrest and the site of frequent clashes between Iranian security forces and Sunni fighters, as well as drug traffickers.
Iran is a key transit route for narcotics smuggled from Afghanistan to the West and elsewhere.