PESHAWAR, Pakistan — Pakistani provincial authorities said Tuesday four or five foreign terrorists were killed in the purported U.S. missile strike that has severely strained relations with this Muslim nation, a key ally in President Bush's war on terror.

Prime Minister Shaukat Aziz, on the eve of a trip to Washington, said that despite the importance of ties with the United States, attacks inside Pakistan "cannot be condoned."

"Pakistan has committed to fighting terrorism, but naturally we cannot accept any action within our country which results in what happened over the weekend," Aziz said, referring to the missile strike Friday in the border village of Damadola.

Eighteen residents, including women and children, were also killed in the strike, the provincial government said Tuesday.

Pakistani intelligence officials have said the target of the attack was al-Qaida's No. 2, Ayman al-Zawahri, who they said was invited to a dinner celebrating an Islamic holiday in the village but sent aides instead.

U.S. counterterrorism officials, however, have not ruled out that Osama bin Laden's chief lieutenant was killed.

In the first official confirmation by Pakistani authorities that militants were killed, the administration of Pakistan's semiautonomous tribal regions bordering Afghanistan said in a statement that the four or five bodies of "foreign terrorists" were taken away "by their companions."

It did not identify them. But a counterterrorism official, who spoke on condition of anonymity because of the subject's sensitivity, said several of those killed were believed to be Egyptian.

Al-Zawahri, an Egyptian, has appeared regularly over the Internet and in Arab media to encourage Muslims to attack Americans and U.S. interests worldwide.

Today, Shah Zaman Khan, director-general of media relations for Pakistan's tribal areas, said the bodies were now probably in "inaccessible mountainous areas" along the rugged, ill-defined border.

The area is a suspected hide-out for al-Qaida and Taliban fighters who sought refuge after the U.S-led war that began after the Sept. 11, 2001 attacks in the United States.

"Efforts are under way to investigate further," Khan said. "The administration is also trying to arrest those clerics who were believed to be there."

Officials believe two area clerics attended the dinner, while al-Zawahri didn't. The clerics are wanted by local authorities for allegedly harboring militants.

There have been conflicting accounts from Pakistani officials and witnesses over who, if anyone, reclaimed bodies from the missile strike scene.

Damadola residents say that all the victims were area residents, and that they buried them all. One Pakistani official told The Associated Press on Saturday that bodies had been taken away for DNA tests, but it wasn't clear by whom.

The statement by the provincial authorities, citing the chief official in the Bajur region where Damadola is located, said its findings were from a report compiled by a "joint investigation team" but gave no specifics on who was on the team.

Pakistani intelligence officials have described the strike as a CIA attack, probably carried out by missiles from a drone aircraft. But neither the Pakistani nor the U.S. government has provided details.

At the Pentagon, Defense Department spokesman Larry Di Rita declined to comment on any aspect of the attack, including whether there was any U.S. military involvement.

The attack has become an embarrassment for Islamabad, a staunch U.S. ally in the war on terrorism. Many in this nation of 150 million people oppose the government's support for the United States in the fight against al-Qaida and the Taliban.

Thousands of Pakistanis took to the streets over the weekend, chanting "Death to America" and calling for the resignation of President Gen. Pervez Musharraf.

Frustration has been growing over a series of suspected U.S. attacks aimed at militants along the porous frontier. The United States has 20,000 soldiers in Afghanistan, but Pakistan says it does not allow them to hunt down or attack militants across the border.