One civilian was killed and two others injured in firing by Pakistan Rangers on the international border in Jammu and Kashmir's Samba district on Friday, police said."Pakistan Rangers resorted to unprovoked firing at BSF (Border Security Force) positions on the international order near Manguchak border outpost this evening. One labourer working in the fields near the BSF outpost was killed and two others are injured," a senior police officer told IANS here."BSF has started retaliating Pakistan's unprovoked firing and heavy firing exchanges are now going on in the area," he added.The injured have been taken to hospital, the official said.