In Pakistan near the Afhgan border, a missile strike from an unknown source killed four people, destroyed a house and damaged two religious schools.
One official suggested that the missiles were launched from Afghan territory, just three kilometers (two miles) away.
The U.S. military and NATO in Afghanistan denied any knowledge of the incident.
The projectiles came down on Saidgi village in North Waziristan, a mountainous region considered a Taliban stronghold and possible hiding place for al-Qaida leader Osama bin Laden.
Two or three people were also wounded in the attack.
Pakistani officials gave conflicting accounts of what happened.
A senior military official in the capital, Islamabad, said the dead and wounded had been making bombs and had accidentally caused an explosion.
However, two local intelligence officials said it was a missile attack, and a government official said the projectiles were apparently fired from Afghan territory.
The intelligence and government officials asked for anonymity because of the sensitive nature of the topic, while the military official said he was not authorized to speak to the media on the record.
Sgt. Timothy Dinneen, a spokesman for the U.S.-led coalition, said the coalition had no reports of the incident.
Lt. Col. Angela Billings, spokeswoman for the separate NATO force, said its troops were not involved.
Habib Ullah, the owner of the house, said five missiles hit the building and two nearby religious schools. He said four of his guests were killed in the house. The attack caused the roof to collapse.
"I don't know whether these missiles were fired from some plane or not, but those killed in the attack were not terrorists," he told an AP reporter near the scene.
Ullah said he had been staying at another house in the village when the attack happened.
He declined to discuss his occupation or answer other questions.
"I am already upset, so don't bother me," he said.
Residents said there was no one inside the schools when they were hit.
Saidgi is in a region from which pro-Taliban militants often launch attacks on government and U.S. troops stationed in Afghanistan.
Pakistan has deployed 80,000 troops along its semiautonomous tribal belt and says American troops are not allowed to operate on its soil. However, weapons fire from the Afghan side sometimes strays over the poorly marked frontier. Also, the U.S. has occasionally launched missile strikes aimed at terror suspects on the Pakistan side of the border.
A January 2006 strike by a U.S. Predator drone in Bajur, another tribal area north of Waziristan, was allegedly targeting al-Qaida's deputy leader Ayman al-Zawahri.
Pakistan intelligence officials said then that while al-Zawahri was not at the site, four other senior al-Qaida militants were killed, although that information was never verified. Thirteen villagers also were killed.
The U.S. has also supplied Pakistan's army with Cobra attack helicopters equipped for night raids, though few details of their operations have been released.
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