Pak warns US troops after exchange of fire

Pakistan warned U.S. troops not to intrude on its territory Friday after the two anti-terror allies traded fire along the Afghan border, straining already tense ties. Thursday's five-minute clash came at a time the United States is stepping up cross-border operations in the frontier region, known as a haven for Taliban and al-Qaida militants. The clash _ the first serious exchange with Pakistani forces acknowledged by the U.S. _ follows a string of other alleged border incidents and incursions that have angered many Pakistanis. Speaking in New York, Pakistan's president tried to play down the incident, saying only that ``flares'' were fired at foreign helicopters that he said strayed into his country from Afghanistan.  U.S. and NATO military officials said the ground troops and helicopters were in Afghan territory.  Pakistani government spokesman Akram Shaheedi urged U.S.-led coalition forces ``not to violate territorial sovereignty of Pakistan as it is counterproductive to the war on terror.'' ``It has been Pakistan's policy that we will not allow anyone to violate our sovereignty, and we will continue to defend our territorial sovereignty,'' he said Friday. The clash occurred as new Pakistani President Asif Ali Zardari was in New York meeting with U.S. Secretary of State Condoleezza Rice, and Afghan President Hamid Karzai was scheduled to meet with U.S. President George W. Bush on Friday. Two American OH-58 reconnaissance helicopters, known as Kiowas, were on a routine patrol in the eastern province of Khost when they received small arms fire from the Pakistani border post, said Tech Sgt. Kevin Wallace, a U.S. military spokesman in Bagram, Afghanistan. There was no damage to aircraft or crew, officials said. U.S. Central Command spokesman Rear Adm. Greg Smith said the helicopters had been escorting U.S. troops and Afghan border police. When the helicopters were fired on, the ground forces fired rounds meant not to hit the Pakistani troops, but ``to make certain that they realized they should stop shooting,'' Smith said from Centcom headquarters in Florida.