The US said on Wednesday that it supported Pakistan's deadly air raid on an Islamic school and praised President Pervez Musharraf for showing "determination" to fight terrorism.
"There was a strike and it was intended to go after al-Qaeda. And the Pakistani government did it on the basis of intelligence that it had gathered and we support them in this," White House spokesman Tony Snow said.
He spoke after armed Pakistani tribesmen ransacked government buildings on Wednesday in protest at a deadly air raid on an Islamic school that officials said was visited by top militants of Osama bin Laden's terrorist network.
A leading human rights group and Pakistani politicians meanwhile called for an independent probe into claims that the 80 people who died in Monday's strike in Bajaur tribal agency were all students and teachers.
"A tactic of the Taliban or al-Qaeda or people on both sides of that border who are trying to commit [acts] of terror -- they are going to do everything they can to create carnage and kill civilians," Snow said.
"We understand it. It makes it tough. And President Musharraf is showing determination, and is in a situation that certainly has its political perils and it requires courage," Snow said.
In a second day of demonstrations against the US and Pakistani governments more than 20,000 people, many brandishing guns, gathered at several rallies in the remote Pashtun tribal belt along the Afghan border.
The biggest protest was at Salarzae village, near the blown-up madrasah, where about 10,000 bearded men demanded Musharraf's resignation.
Anti-Western feeling has been high amid allegations by Islamist leaders that US forces based in Afghanistan either launched the raid themselves using Predator drones or ordered Pakistan to carry it out.