Gunmen opened fire on the top US diplomat in northwestern Pakistan early Tuesday as she left for work in her armored vehicle, police and embassy officials said. No one was killed or wounded in the shooting. Lynne Tracy, principal officer for the consulate in the bustling city of Peshawar, was 100 meters from her house when two men with AK-47s jumped out of their dark blue Land Cruiser and sprayed her car with dozens of rounds of ammunition. Her driver reversed the vehicle and peeled back to her home, said Arshad Khan, the local police chief and senior investigator in case. The brazen attack came hours after the collapse of the ruling coalition that drove US ally Pervez Musharraf from the presidency one week ago, throwing more power to Asif Ali Zardari, the widower of assassinated ex-leader Benazir Bhutto. His party, which holds the largest bloc in Parliament, moved almost immediately to calm US fears that the 5-month-old government was paying too little attention to Islamic militants, banning the Taliban following a string of suicide bombings.