Demonstrations were held across Pakistan on Tuesday, a day after dozens of men were killed when the army launched missiles at a religious school alleged to be an al-Qaeda training camp.

In the largest protest, at least 20,000 men — many of them armed with Kalashnikov rifles and grenade launchers — packed the town of Khar in the northwestern tribal district of Bajur.

They condemned both U.S. President George W. Bush and Pakistani President Gen. Pervez Musharraf, blaming both for the missile attack on the religious school, or madrassa, in the nearby village of Chingai.

Chanting "Death to Bush! Death to Musharraf," and "Anyone who is a friend of America is a traitor," angry villagers and Muslim clerics called for nationwide protests following the strike, which was the country's deadliest military operation against suspected militants.

'We will carry out these suicide attacks soon.'-Tribal elder threatens Pakistani security forces

A tribal elder known to have pro-Taliban sympathies said he had recruited a "squad of suicide bombers" to target Pakistani security forces.

"We will carry out these suicide attacks soon," the elder told the crowd, which roared back in unison, "Yes!"

Pakistan's army said its helicopters fired five missiles into the school after the government identified it as an al-Qaeda training camp.

The attack flattened the building and killed 80 people inside. Musharraf said the dead were all militants, but the tribesmen claim civilians were among the dead. Three men survived with serious injuries.

School visited by top terrorism suspects, official says

An unnamed Pakistani intelligence official told the Associated Press that the seminary had been visited in the past by Ayman al-Zawahri, who is al-Qaeda leader Osama bin Laden's deputy and ranks near the top in international lists of terrorism suspects.

The official also said the school was visited by an Egyptian suspected of involvement in a plot to blow up trans-Atlantic airliners, which was foiled by British authorities in August.

Maj.-Gen. Shaukat Sultan, a Pakistani army spokesman, initially told the Associated Press that U.S. forces did not take part in the attack on the school. But he said Pakistan received intelligence from U.S. forces in Afghanistan. He later denied making such comments.

The unrest caused Britain's Prince Charles, travelling in Pakistan, to cancel a planned trip to Peshawar in the country's northwest. The rugged, mountainous tribal districts that line the Afghan border outside Peshawar are not governed by Pakistani law and are a hotbed of support for the Taliban.

With files from the Associated Press