PESHAWAR, Pakistan - Thousands of Pakistanis took to the streets Sunday to rage for a second day against a purported U.S. attack on a border village, chanting "Death to America" and demanding U.S. troops leave neighboring Afghanistan, as more details emerged about the airstrike.

Pakistani intelligence officials said the reported target, al-Qaida No. 2 leader Ayman al-Zawahri, had been invited to the attacked village for a dinner marking a Muslim festival on the night of the missile strike but he failed to show up.

With the government's alliance in the U.S.-led war on international terror groups already unpopular in this Muslim country, the deaths of at least 17 people in Friday's attack have stoked widespread anger.

Some 10,000 people demonstrated in Karachi, Pakistan's biggest city, chanting "Death to America" and "Stop bombing against innocent people." Hundreds also rallied in Islamabad, Lahore, Multan and Peshawar, burning U.S. flags.

Protesters demanded an end to the U.S. presence in Afghanistan, where loyalists of the ousted Taliban regime and other militants are battling an Afghan government supported by American and other foreign troops. Many insurgents are believed to use Pakistan's border region as a haven.

Ghafoor Ahmed, a leader in the coalition of Islamic groups that organized Sunday's rallies, told demonstrators in Karachi that Pakistan's president, Gen. Pervez Musharraf, should resign.

"The Army cannot defend the country under his leadership," Ahmed said.

Hundreds of riot police, wielding batons and shields, were deployed in Karachi, but the rally ended after an hour with no reports of violence.

On Saturday, about 8,000 tribesmen protested in a town near the attacked village, Damadola, and a mob set fire to the office of a U.S.-backed aid agency in another nearby hamlet.

Two Pakistani intelligence officials said Sunday that al-Zawahri, who has a wife from a tribe prominent in the region around Damadola, had been invited to a dinner in the village to mark last week's Eid al-Adha holiday, but apparently changed his mind.

One of the officials said al-Zawahri sent some aides instead and investigators were trying to determine whether any were in the three houses destroyed in the attack.

The officials agreed to discuss the situation only if their names were not used, because they are not authorized to speak to journalists. They said their information came from Pakistan's security agencies and intelligence shared by the CIA after the attack.

Pakistan says it does not allow American forces on its soil to attack or hunt militants. On Saturday, the government condemned the attack and lodged a diplomatic protest, saying it had killed innocent civilians.

David Almacy, a White House spokesman, declined to comment directly on the airstrike, saying only, "President Musharraf is a valued ally and partner in the war on terror, as is Pakistan."

But Sen. John McCain, R-Ariz., and other American lawmakers defended the airstrike.

"This war on terror has no boundaries," McCain, a former Navy combat pilot who challenged George W. Bush for the Republican presidential nomination in 2000, told CBS. "We have to go where these people are, and we have to take them out."

In a sign of tensions over the attack, two top Pakistani officials - one from the military, the other from the civilian administration - said privately that the government was only informed of the strike after it happened.

However, U.S. Sen. Evan Bayh, a Democratic member of the Senate Intelligence Committee, said he had "every reason to believe" high-ranking officials in the Pakistani government knew in advance.

Many in this nation of 150 million people oppose the government's ties with Washington and there is increasing frustration over a recent series of suspected U.S. attacks along the rugged frontier aimed at militants.

Bayh said the problem is the Pakistani government does not control the border region where Osama bin Laden, al-Zawahri and other militants are believed to have been hiding since the U.S.-led military ouster of Afghanistan's hard-line Taliban regime for hosting al-Qaida.

"It's a regrettable situation, but what else are we supposed to do?" Bayh told CNN. "The Pakistani border is a real problem."

One of the Pakistani intelligence officials said 12 bodies, including seven foreigners, had been taken from Damadola, which is about four miles from Afghanistan. He said the bodies were reclaimed by other militants, but another Pakistani official said Saturday that some were taken away for DNA tests.

It was not possible to reconcile the conflicting accounts, which reflect widespread confusion over the attack and the refusal of the government to comment publicly on the details of what happened.

Residents of Damadola, which is in the tribal region of Bajur, insisted no militants were staying in the village and all the dead were local people.

But the high-level civilian Pakistani official said the government had been investigating reports that al-Zawahri had visited Bajur in recent months - a tip gleaned from the interrogation of Abu Farraj al-Libbi, a senior al-Qaida figure arrested in Pakistan in May.

Al-Libbi is accused of masterminding two failed assassination attempts on Musharraf in 2003 that killed 17 people. He was interrogated in Pakistan and later handed over to the United States.

Thousands of men from Bajur and other nearby tribal areas crossed into Afghanistan to fight against the U.S.-led offensive that toppled the Taliban after the Sept. 11, 2001, terror attacks on America.

The governor of the Afghan province across from Bajur said Afghanistan's government had formed a 1,000-man tribal militia to watch the border and stop Islamic militants from infiltrating.

"But the border is so long and so rugged that it's easy for them to come and go," Kunar Gov. Assadullah Wafa said.