Pakistan's top security officials on Wednesday were searching for clues that a "moderately important terrorist target" may have been hit when U.S. and/or NATO forces attacked three houses in a remote part of the country's border region with Afghanistan.
As many as 15 people were killed in the early morning strike Wednesday.
This was a commando raid by U.S. special operations forces - the first known use of ground troops inside Pakistan - in an attempt to kill or capture a high value target, reported CBS News national security correspondent David Martin. Until Wednesday, all known attempts to kill terrorist leaders operating out of Pakistan had been conducted by unmanned drones.
The operation took place near the village of Angor Adda in Pakistan's South Waziristan region - a notorious sanctuary for al Qaeda and Taliban militants. Eyewitnesses said the strike involved helicopter gunships.
South Waziristan and the adjoining North Waziristan regions are known to harbor fighters who routinely cross the border into Afghanistan to attack U.S. and other Western troops then return to the relative security of Pakistani soil.
U.S. officials told Martin a small team of commandos crossed the border from Afghanistan into Pakistan to go after an al Qaida cell operating out of a village less than a mile from the border. The officials said the cell was using the village as a base to plan and conduct cross border raids into Afghanistan.
The leader of the cell - whose name the officials did not release - was reported killed along with several women and at least one child. The American military maintains the women were shot because they were firing at U.S. troops. Martin said the officials did not dispute local reports placing the death toll at or near 15.
The reported use of ground troops prompted immediate speculation that the attack was aimed at an important terrorist target, but also enraged local residents and authorities, who have long insisted that Western forces must not enter Pakistani territory.
"I don't know if there were any top targets. But there could well be moderately important terrorist targets," the security official told CBS News. "If there was deployment of grounds troops, which involved a greater risk than sending in a pilot-less drone, that suggests the attackers were probably looking for a specific terrorist target."
Meanwhile, there were conflicting reports Wednesday about whether Pakistani Prime Minister Yusuf Raza Gilani had survived an assassination attempt when shots were fired at his motorcade near Islamabad's international airport. (.)
An eyewitness from the village that was struck in South Waziristan said nine people were killed in one house - all of them locals with no ties to militants, including at least five women and children.
Khan Gul Wazir told CBS News by telephone on Wednesday that he had been awake for early morning prayers when he heard loud gunfire and explosions. He said he ran outside and saw smoke pouring from one of his neighbor's homes.
Wazir said he saw American troops surrounding the house and blocking off the area. He also reported five U.S. helicopters hovering over the area for the duration of the operation, which he said lasted one hour.
A spokesman for the Governor of Pakistan's Northwest Frontier Province, who also officially administers the North and South Waziristan, told CBS that 20 people had been killed in the raid, including women and children. His office officially condemned the attack as a violation of Pakistan's territorial sovereignty.
A Pakistan army spokesman warned that the apparent escalation from recent foreign missile strikes on militant targets along the Afghan border would further anger Pakistanis and undercut cooperation in the war against terrorist groups.
U.S. rules of engagement allow American troops to pursue militants across the border into Pakistan when they are attacked.
However, Pakistan army spokesman Maj. Gen. Athar Abbas said hot pursuit wasn't an issue, adding that the attack "was completely unprovoked." He said Pakistani troops were near the village and saw and heard nothing to suggest the U.S. forces were pursuing insurgents.
U.S. military and civilian officials declined to respond directly to Pakistan's complaints. But one official, a South Asia expert who agreed to discuss the situation only if not quoted by name, suggested the target of any raid like that reported Wednesday would have to be extremely important to risk an almost assured "big backlash" from Pakistan.
There is no indication the target was al Qaeda leader Osama bin Laden or his deputy, Ayman al-Zawahri, officials told Martin in Washington.
Wazir told CBS that in addition to the house where nine people were killed, two other nearby homes were hit in the village, which sits close to the border with Afghanistan. He said he saw the bodies of no "strangers" among the dead.
A local tribal elder who acts as a go-between for the community and the government said the villages in the area are often subjected to violence because militants use peoples' homes to take shelter after crossing border, with or without their consent.
Wazir said the situation for he and his neighbors had grown far worse since President Pervez Musharraf's decision to resign under huge domestic pressure about two weeks ago.
A Taliban militant from the area claimed Wednesday's was not the first such ground operation. He told CBS News U.S. helicopters landed in a village three weeks ago, kidnapped one person from a house and injured an old man inside. The militant also said the number of U.S. aircraft - mostly the pilotless drones - flying over North and South Waziristan had increased "300 percent" during the past month.
The CIA and other Western intelligence agencies are known to have scrutinized intelligence coming from North and South Waziristan in the past in their searched for some of al Qaeda's top leaders; most notably bin Laden and al-Zawahiri.
The Pakistani security official who spoke to CBS News said Pakistani military and intelligence forces in the region had also carried out an intense search for al Qaeda's leaders as recently as last month, based on "information which provided to us with some new clues."
The Pakistani official refused to elaborate on the nature of that information but said "the situation in Waziristan remains of immense interest to all of us."