The paramilitary force personnel entered the Gul Muhammed Lane on late Wednesday night and began search operation.
The Rangers carried out a targeted raid in the locality on a tip-off regarding presence of criminal elements. However, the gangsters retaliated with heavy arms, thus ensuing exchange of gunfire.
One of the personnel was also injured in the gunfire by terrorists.
The law enforcement personnel cordoned off the area to catch the culprits. However, all of three were gunned down in the encounter.
Rangers spokesperson said heavy cache of arms was recovered from possession of criminals.