The US military has killed at least 11 Pakistani soldiers in an air strike close to the Afghan border.
The soldiers were manning a border post that was hit by a US missile in the Mohmand region last night. Officials say the incident happened during a cross-border skirmish between the US military and Taliban militants.
State-run Pakistan Television said eight civilians were also killed during the raid. It reported that foreign forces tried to establish a military post and were resisted by tribesmen. An airstrike then struck a Pakistani military post, PTV said.
Security officials confirmed that troops had crossed the frontier and tried to occupy the strategic Pakistani post in the mountainous Gora Prai area.
The Pakistani military condemned the attack as an act of aggression within Pakistan's border that "hit at the very basis of cooperation" in the war on terrorism.
"We condemn this completely unprovoked and cowardly act on the FC [Frontier Corps] post and regretted the loss of precious lives of our soldiers," a Pakistani military statement said.
"A strong protest has been launched by the Pakistan army and we reserve the right to protect our citizens and soldiers against aggression."
US-led NATO forces have launched several air strikes inside Pakistan's tribal areas within the last year. The US military has in the past used unmanned drones to attack suspected militants inside Pakistan.
The United States has not yet commented on the incident.