A Pakistan provincial governor on Wednesday confirmed coalition troops from across the Afghan border had raided a Pakistani village, calling the incident "a direct assault" on sovereignty.

The raid killed at least 20 people, North West Frontier Province governor Owais Ahmed Ghani said in a statement.

"Innocent citizens of Pakistan including women and children were martyred," he said.

"This is a direct assault on the sovereignty of Pakistan and the people of Pakistan expect that the armed forces of Pakistan would rise to defend the sovereignty of the country and give a befitting reply to all such attacks," he added.

Earlier a security official told AFP that 15 people had died in the pre-dawn attack in the village of Jalal Khel in South Waziristan, a tribal area bordering Afghanistan that is a known hub of al Qaida and Taliban militants.

A spokesman for the NATO-led International Security Assistance Force (ISAF) in Afghanistan said he was not aware of such an operation.

He added that ISAF does not have a mandate to attack outside the borders of Afghanistan unless its troops come under fire from within Pakistan, in which case the force can respond with artillery.

The US-led coalition in Afghanistan also said earlier that it was unaware of any such incident.