TEHRAN, Iran

At least 11 police officers were killed in an armed attack on a police station in Iran's southeastern Sistan and Baluchistan province on Friday, officials said.

The attack on a police station in Rask city was carried out by a group of "terrorists," the state media reported, citing a police spokesman, who called the attack "cowardly."

Some assailants were killed, while others injured and taken into police custody.

The Jaish e Adl group, which has an active presence in the province bordering Afghanistan and Pakistan, reportedly claimed responsibility for the overnight attack.

Authorities in Sistan and Baluchistan province, providing details about the attack, said the attack took place at around 2:00 a.m. local time (2230GMT on Thursday), adding that the situation has been back to normal.

Iran's police chief Ahmed Reza Radan has issued "urgent orders" to senior police officials to investigate the attack, the state-run IRNA news agency said, citing a police spokesman.

Sistan and Baluchestan province has witnessed several attacks on security forces in recent years, which Iranian authorities have blamed on local terrorist groups.

The attack on Friday comes five months after two police officers were killed in the province by unidentified assailants.