NATO has admitted it is "highly likely" it was responsible for an attack by warplanes and helicopters that killed dozens of Pakistan soldiers on an Afghan border post near Mohmand. Pakistan forces returned fire.
"Pakistan's sovereignty was attacked early this morning," said Pakistani Prime Minister Yousuf Raza Gilani. "This is our Pakistan and we have to defend it," told the Wall Street journal.
"Close air support was called in, in the development of the tactical situation, and it is what likely caused the Pakistan casualties," Brig. Gen. Carsten Jacobson, a spokesman for NATO said. He apologized.
News reports said NATO forces were involved in an anti-Taliban operation in the Khyber region of northwestern Pakistan near the Afghan border.
Relations between Islamabad have deteriorated as the war seems to drone on without end. And U.S. military and government officials have accused Pakistan of giving some of the ammunition and other aid it delivers to anti-Afghanistan government groups.
In some cases NATO forces allegedly were killed with these munitions.
Pakistan was outraged by the Navy Seal attack inside its territory that resulted in the execution of Osama bin Laden.
Afghan President has simultaneously criticized the U.S. for allegedly killing civilians not involved in the conflict.
In the U.S., support for the war has declined as casualties climb at the same time American commanders say they are winning. Intense pressure to cut government spending adds to the pressure to pull out of the graveyard of empires.
Pakistan, meanwhile, said it returned fire on the attack early Saturday. There was no information on NATO suffered casualties.
"Pakistani troops effectively responded immediately in self-defense to NATO's aggress with all available weapons," its military said in a statement.