At least four persons were killed and two others were wounded as two rival tribal groups clashed over some dispute in Bolan district of southwestern Pakistani province of Balochistan on Saturday. According to the Assistant Commissioner, the rivals dug trenches and exchanged fire with heavy weapons in Tehsil Bhag of Bolan district killing at least four people and wounding two others. He further said Levies\' (paramilitary force) reinforcement was called in to control the situation and the security forces cordoned off the area. The wounded people were shifted to a nearby hospital by rescue teams. Moreover, at least 350 bags of ammonium chloride and acid bottles were recovered and two persons taken into custody in a raid at a warehouse on Basant road near Mission Chowk of Balochistan province by Frontier Constabulary (FC). The security forces said these large amounts of ammonium chloride recovered were to be used in making explosives.