More than 5,000-armed men rallied in Pakistan's tribal belt on Friday, ahead of planned countrywide protests against an airstrike on an Islamic school in which 80 people were killed.
The demonstrations were the latest in a series against Monday's raid, which the government said its forces launched because the madrassa doubled as an Al-Qaeda training camp. Locals say the dead were merely students.
"The people of Bajaur are 100 percent convinced that the attack was launched by US forces," tribal elder Akhunzada Chatan told over 3,000 people in Khar, the main town in Bajaur district, near the site of the attack.
Another 2,000 tribesmen waving assault rifles in the air chanted anti-government slogans in the small tribal town of Enayat Killi. Speakers denounced the killing of "innocent students and teachers".
In the main northwestern city of Peshawar US fast food chain KFC closed for the day and other shops hung banners inscribed with Koranic verses over their windows amid fears of rioting.
The national protest call came from Pakistan's biggest alliance of hardline Islamic parties, the Muttahida Majlis-e-Amal (MMA - United Action Forum).
MMA secretary general and leader of the opposition in Pakistani parliament Maulana Fazlur Rehman will lead the rally after attending Friday prayers in the city's historic Mahabat Khan mosque, a spokesman said.
Traffic was already thin in Peshawar, where violent protests over cartoons of the Prophet Mohammed in February left two people dead and western businesses -- including the KFC branch -- in flames.
The MMA said protests would be held in other cities and towns including the volatile southern port of Karachi, Pakistan's largest city, alliance spokesman Shamim Shamsi said.
"We have said our protest will continue until the government holds an impartial inquiry," Shamsi said.
Throughout the week tens of thousands of armed protesters have rallied in the Pashtun tribal belt bordering Afghanistan, shouting slogans against the US and Pakistan governments and on one occasion smashing up official buildings.
Pakistan says its helicopter gunships destroyed the religious school because it was being used as an Al-Qaeda-linked training camp.
The terror network's deputy Ayman al-Zawahiri was a past visitor there, security officials have said.
But local leaders say it was a US military operation, possibly involving a missile fired from a Predator drone.