Mortar and artillery shells fired by the U.S. military at suspected militants in Afghanistan landed in Pakistani territory Sunday, but no one was injured, a Pakistani army spokesman said. The shooting in the early hours of Sunday morning occurred when the U.S. troops were operating in Afghanistan's Paktika province, near the Pakistani border village of Alwara Mandi in the North Waziristan tribal region, said spokesman Maj. Gen. Shaukat Sultan, according to AP. Sultan said the U.S. commander in the area had informed his Pakistani counterpart that since they were engaged in a «skirmish with miscreants» _ a byword for militants _ very close to the Pakistani border, the possibility of some rocket or artillery fire landing in Pakistani territory could not be ruled out. «Certain shells did land in Pakistani area but there was no collateral damage,» Sultan said. There was no immediate comment from the U.S. military. The border between Pakistan and Afghanistan, which runs through rugged mountains and deserts, is not marked in places, and gunfire and bombs fired by U.S. soldiers and fighter jets in Afghanistan have landed in Pakistani territory in the past. Pakistan is an ally of the United States in the war against terrorism, and has deployed thousands of troops in the regions bordering Afghanistan to hunt down terror suspects.