KARACHI, May 30: A security guard was killed and his associate was injured when their colleague opened fire on them outside the building of International Gateway Exchange at Marston Road in the early hours of Friday.

Police said Nauman Mughal, 35, died on the spot, while Syed Amir Raza, 34, was injured when their colleague Tasawwar Husain sprayed them with bullets and fled.

Police sources said an altercation took place between them over the possession of a bench to sleep on.

The dispute between them began at around 12 midnight. Around 4am, Tasawwar Husain got up and opened fire on Nauman who was sitting on a chair within the premises of the exchange. The victim suffered three bullet wounds in the chest, police said.

Syed Amir Raza also suffered serious injuries and was shifted to the Civil Hospital for treatment.

Police said all the security guards belonged to the Police Foundation were working under the supervision of a retired colonel. They said the absconding suspect hailed from Balochistan.