At least 11 Iranian police officers were killed in an attack overnight by militant group Jaish al-Adl (Army of Justice) on a police station in the southeastern province of Sistan-Baluchistan, an official told state television on Friday.

A number of assailants were also killed in a shootout that ensued with the security forces, the channel reported.

“In the terrorist attack on the police headquarters in the town of Rask, 11 policemen were killed, and others were wounded,” Alireza Marhamati, deputy governor of the province, told state TV.

The attack, which occurred around midnight, was one of the deadliest in years for the region lying close to Iran’s border with Afghanistan and Pakistan.

It was claimed by Jaish al-Adl, in a brief statement on its Telegram channel. Jaish al-Adl was formed in 2012 and is blacklisted by Iran as a “terrorist” group.

“The officers at the targeted police station defended themselves bravely and wounded and killed some of the assailants,” Marhamati was quoted as saying later by the official news agency IRNA.

Seven police officers were wounded, with some in critical condition, Zahedan prosecutor Mehdi Shamsabadi told IRNA.

The Sistan-Baluchistan police commander was present at the scene of the attack, and the situation is now under control, the news agency said, adding that an investigation into the attack was opened.

The ISNA news agency published footage of a helicopter searching for the attackers above mountains on the Pakistan-Iran border.

Spate of attacks

Deputy Interior Minister Majid Mirahmadi said on television that “one of the terrorists had been arrested” by the security forces.

The attackers were unable to escape to the other side of the border and the security forces had secured the whole region, he added.

Unrest in the impoverished Sistan-Baluchistan province has involved drug-smuggling gangs, rebels from the Baluchi minority, and religious extremists.

Similar attacks have occurred previously, including on July 23 when four policemen were killed while on patrol.

That came two weeks after two policemen and four assailants were killed in a shootout in the province, also claimed by Jaish al-Adl.

In May, five Iranian border guards died in clashes with an armed group in Saravan, southeast of Zahedan, the provincial capital of Sistan-Baluchistan.

State media reported at the time that the attack was carried out by “a terrorist group that was seeking to infiltrate the country”, but its members “fled the scene after suffering injuries”.

In late May, IRNA quoted a police official, Qassem Rezaee, as saying “Taliban forces” had shot at an Iranian police station in Sistan-Baluchistan, a drought-parched region. The two countries have been arguing over water rights.

Zahedan, one of the few Sunni-majority cities in predominantly Shiite Iran, was also the scene of months-long deadly protests that erupted in September last year over the alleged rape of a teenage girl by a police officer.

The September clashes in Zahedan occurred as Iran was gripped by nationwide protests following the death in custody of 22-year-old Mahsa Amini, arrested for an alleged breach of strict dress rules for women.