Four police forces were injured in an assault by a gunman in downtown Tehran, Iran’s official news agency IRNA reported on Saturday, adding that the assailant was injured and arrested.

Ali Salehi, Tehran’s public and revolutionary court prosecutor said that a man fired at police officers stationed in front of the building of Foundation of Martyrs and Veterans Affairs.

He added "four police officers" were injured in the incident and taken to hospital for treatment. According to reports, a passerby was also injured during the shooting. 

Noting that the assailant was also shot and arrested, Salehi said that the man also killed four people and injured two others in the city of Shahriar west of Tehran with a firearm on Friday and fled the scene. 

Hossein Rahimi, the head of the Tehran police, said that preliminary investigations showed the assailant committed the criminal act following a years-long property dispute with some of the victims in the earlier shooting.

Rahimi added that the assailant was spotted Saturday morning near the Martyrs Foundation building and was identified by the officers present at the scene, and he immediately started shooting at them.

No further details were immediately available about the case, but Rahimi said investigation is still underway about the case.