Three NATO containers were torched by unknown gunmen in Pakistan\'s southwest province of Balochistan on Sunday, reported local media DAWN. According to the report, unknown gunmen riding on a motorbike opened fire at a NATO convoy carrying goods for the NATO troops in Afghanistan near the province\'s capital Quetta. The attack came when the convoy parked at a roadside tea stall, said local police, adding that the gunmen set the trucks on fire after pouring petrol on them. No casualties were reported in the attack, said the police. Police are investigating into who have attacked the convoy, but no clues have been found. So far no group has claimed responsibility for the attack yet. NATO convoys frequently come under attacks by militants in Balochistan as many such supply trucks have to pass through Balochistan before they reach Afghanistan. It is reported that nearly 70 percent of the supplies for the 140,000 NATO troops stationed in Afghanistan are shipped into Afghanistan through the land route in Pakistan. As NATO convoys are frequently attacked in Pakistan, the NATO has to ship some of its supplies into Afghanistan from the northern part via the Central Asian countries though at a much higher cost.