At least two-thirds of the people killed in the strike in North Waziristan were believed to be Islamic militants, but it was not clear whether any senior figure was among the dead. Local residents said they believed the attack was launched from a U.S. Predator drone. The unmanned aircraft have long been used against targets in the tribal areas, but such strikes have become much more frequent over the last two months.

News reports identified 16 of the dead as "foreigners" - a term usually meant to describe insurgents from Arab countries or Central Asia. Two women and a child also were reported killed in the strike, which was the second of its kind in the tribal areas this week and the eighth in the last month.

A Pakistani military spokesman, Maj. Gen. Athar Abbas, said he had no information about the missile strike.

U.S.-launched strikes inside Pakistan are a highly contentious topic. The country's new civilian leadership says it supports the war on the Taliban and al-Qaeda, but also has insisted that Pakistan's sovereignty be respected.

Tensions have been growing over the American attacks. Over the last two weeks, Pakistani troops and villagers have fired at U.S. aircraft at least twice. In yesterday's attack, tribesmen shot in the direction of the Predator, according to witnesses.

The U.S. strikes are extremely unpopular with Pakistanis, many of whom believe the Bush administration is running roughshod over their own leaders. Anger peaked over a rare cross-border raid by U.S. ground forces on Sept. 3.

The compound targeted yesterday, in the Momadkhel district, close to the Afghan border, was believed to be owned by two Afghan nationals.

A strike earlier in the week killed eight people in the nearby village of Khushali Toori Khel.

Militants in the border region are blamed for rising attacks on U.S. troops in Afghanistan and attacks within Pakistan, including the Sept. 20 truck bombing of the Marriott Hotel in Islamabad that killed more than 50 people.

Yesterday, Pakistan's Interior Minister Rehman Malik said the country's war against Islamic extremists would go on until it is "terrorism-free."

Malik said the current government, which came to power after February elections, would fight until militants were either killed or forced to flee Pakistan.