Two Afghan warplanes were hit over Pakistan by missiles from U.S.-made Pakistani F-16s and were believed to have been destroyed, the Defense Ministry said. A ministry statement said the two planes were among six Afghan aircraft that intruded into Pakistani airspace north of Nawagai, 120 miles northwest of Islamabad, with the intent of bombing targets there. It said all Pakistani planes returned safely from the mission. The statement gave no further details. Last week, Pakistan said it downed an intruding Afghan plane in the same area, but Kabul disputed the claim. Kabul accuses Islamabad of aiding Muslim guerrillas fighting the Afghan government.