KARACHI: Eighteen-yearold Irfan was shot dead in Surjani Town on Wednesday, according to police.While riding a motorbike Irfan sustained critical injuries when an unknown bike rider opened fire on him in Khuda Ki Basti. He was taken to Abbasi Shaheed Hospital where he died during treatment.Surjani SHO Ghulam Rasool quoting witnesses said that both the victim and suspect were talking to each other while riding their respective bikes. An exchange of hot words ensued between themand the suspect then bred and fled. The victim was a vegetable seller in the area. The officer said that they were waiting for relatives to lodge an FIR to ascertain the possible motive and identity of the killer.