Islamabad, Pakistan (CNN) -- Armed militants on motorcycles in southwest Pakistan ambushed and set ablaze a convoy of tankers contracted to NATO forces in Afghanistan on Sunday night, police said. The gunmen opened fire after forcing the convoy of eight oil tankers to stop in an area 90 kilometers (55 miles) southwest of Quetta, the capital of Balochistan province, police official Abdul Qadir said. The militants killed one of the truck's drivers and set the tankers on fire before they escaped, Qadir said. Fuel and supply trucks contracted to supply NATO have been left stranded in Pakistan by Islamabad's decision to block its two NATO supply routes to Afghanistan.Gunmen on motorcycles force the convoy to stop and then open fireAt least one driver is killed, police sayPakistan closed NATO supply routes into Afghanistan after an airstrike killed PakistanisThe airstrike prompted a diplomatic crisis between Pakistan and the United States
On Thursday, militants armed with rocket-propelled grenades and automatic weapons attacked and destroyed more than 20 NATO-bound oil tankers just outside _.