Pakistan: militant gunman attack convoy of Nato tankers bound for Afghanistan By Rob Crilly, Islamabad Published: 6:55AM BST 01 Oct 2010 Suspected militants, with their faces covered, opened fire with small arms to scare off the drivers and then set fire to the vehicles, which were parked in Shikarpur just before dawn, said Abdul Hameed Khoso, the district police chief. "Around 20 attackers armed with rocket launchers and assault rifles attacked these trucks. They set ablaze 27 trucks parked there," he said. Some 80 per cent of supplies for international forces pass through Pakistan. Although attacks by militants and looters are not rare, the latest incident comes at a time of heightened tension between Islamabad and Nato commanders in Afghanistan. Three Pakistani soldiers were killed and three wounded on Thursday in two cross-border strikes by Nato helicopters forces chasing militants in Pakistan's northwestern Kurram region. The Nato-led International Security and Assistance Force initially denied crossing the border before later admitting that its troops had entered Pakistani air space. Hours later, Pakistani authorities halted tankers carrying supplies for Nato forces passing through the Khyber tribal region on the Afghan border. Pakistan is a crucial ally for the United States in its efforts to stabilise Afghanistan, but analysts say border incursions and disruptions in Nato supplies underline an increasingly fraught relationship. This week the country's ambassador to Brussels was ordered to submit a formal protest to Nato headquarters over three earlier, unauthorised attacks. "Isaf/Nato has been asked not to participate in any military action that violates the UN mandate and infringes upon Pakistan's sovereignty," said a statement issued by the foreign ministry. "In the absence of immediate corrective measures, Pakistan will be constrained to consider response options."