Automatic gunfire echoed across the area as the builders' gunmen attacked each other in the presence of well-equipped police and Rangers personnel.
Malik Riaz Hussain and Malik Tabarak Bari along with scores of their armed security guards reached the district and sessions court in connection with an inquiry ordered by the chief justice of Pakistan on October 26 into the killing of a security guard during another gun battle between the two rival groups over a piece of land on August 13, 2008.
Shortly after leaving the courtroom, the two building tycoons exchanged harsh words which led to a brawl between their security guards. Soon, it triggered the gun battle during which they freely used automatic and assault rifles for over half an hour till the two builders left the scene without any hurdles.
A security guard - Hamid, 35, - of Malik Bari died on the spot while six gunmen belonging to both the groups suffered injuries.
A police team deployed at the scene in connection with the district bar election also came under fire and its supervising officer DSP Malik Naeem Iqbal suffered a bullet injury.
The police swung into action only after the two big-shots left the scene and arrested 12 of the gunmen. Later, they were shifted to the Margalla police station along with nine vehicles including a Sport Utility and a double cabin as well as assault rifles including SMGs, guns and pistols.
Later, the police also raided Federal Government Services Hospital and took into custody six more gunmen involved in the incident.
The incident took place in front of the district and session judge's courtroom where offices of the chief commissioner, deputy commissioner, additional deputy commissioner, SSP and two superintendents of police are also situated.
Heavy contingent of police along with personnel of Rangers armed with sophisticated and assault weapons are also deployed in and around the offices for security and checking entry of weapons and explosives.
On Saturday, an additional well-equipped contingent of police was also deployed on the premises in connection with the lawyers' election.
Besides, the entry and exit points of the area are also blocked and only government officers concerned are allowed to bring in their vehicles.
However, over two dozens armed security guards of the two builders riding vehicles entered the area and later fled without any hindrance.
The incident was considered as a serious security lapse by the police and city administration which put the lives of senior officers of police, administration and judges along with hundreds of lawyers and court visitors at risk.
A police officer said it was suspected that some high-ranking officers had allowed the two rivals to enter the premises with weapons.
An officer on condition of anonymity told Dawn that the police and the city administration remained silent spectators due to influence of the two builders. They reacted only to save their own lives, he added.
Most of the police and administration officers were not available for comments while some with whom this reporter spoke were reluctant to talk on the incident.
It may be recalled that the inquiry was ordered by the CJ after a widow, Shahmraz Bibi, accused Malik Riaz of killing her husband, a DHA security guard, on August 13, 2008.