Women and children were among 15 people killed in an attack yesterday involving US-led forces in a Pakistani village near the border with Afghanistan, officials and a resident said.
Pakistan's government said that the cross-border raid involving US-led or Nato forces killed several civilians in a village near the Afghan border.
A statement from the Foreign Ministry described the raid in the South Waziristan region as a ground attack supported by air assets based in Afghanistan.
It said the attack caused "immense loss of civilian life" and called it a "gross violation" of Pakistani territory.
The statement said such strikes undermine joint efforts to fight terrorism.
South Waziristan is considered a militant stronghold, and the U.S. has pushed Pakistan to crackdown on insurgents who use it as a base to stage attacks inside Afghanistan.
However, both the coalition and separate NATO-led security force in Afghanistan said they had no knowledge of any such attack.
1st Lt Nathan Perry, a spokesman for the US-led coalition in Afghanistan, said it had "no information to give" about the alleged operation, while a spokesman for NATO troops there denied any involvement in the incident which reportedly took place in the remote tribal area that has become a haven for Al-Qaeda and Taliban fighters
Officials gave differing accounts of the pre-dawn raid in the South Waziristan region, part of the tribal belt where officials suspect Osama bin Laden and al-Qaida No. 2 Ayman al-Zawahri are hiding. It was unclear whether any militant leaders had been killed or captured.
The governor of North West Frontier Province, the chief administrator for the tribal belt, said three coalition helicopter gunships and commandos carried out an "outrageous" attack on a village. Mukhtar told reporters in Lahore.
Meanwhile as many as 30 suspected militants were killed in clashes with Pakistani troops in the troubled northwestern Swat valley yesterday, the army said.
"Up to 30 militants are confirmed dead and some 25 wounded in a ground and air offensive by the army troops," spokesman Major Nasir Ali told AFP.
Ali said the operation targeted the central headquarters of radical pro-Taliban cleric Maulana Fazlullah, also known as Mullah Radio, whose followers have been engaged in bloody clashes with troops since late last year.