At least 11 Iranian police officers were killed in a jihadist-claimed attack overnight 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 the Sunni Muslim jihadist Jaish al-Adl (Army of Justice) group, 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, reports AFP.
The ISNA news agency published footage of a helicopter searching for the attackers above mountains on the Iran-Pakistan border.
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 Sunni Muslim 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, claimed by Jaish al-Adl.
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