Militants fired at the vehicles of Sashastra Seema Bal (SSB) which were ferrying the personnel to their camp after performing law and order duties in the city, a security force official said.
He said four SSB personnel sustained injuries in the attack. The injured have been admitted to a hospital for treatment.
Security forces immediately cordoned off the area and launched search operations to track down the militants.
This is the first militant attack in the city since the encounter at Nowhatta on August 15 in which a CRPF commandant was killed and nine other personnel were injured.