Attackers late Thursday beheaded a 45-year-old Islamic school teacher and pumped his body full of bullets near Makin, a town in North Waziristan district bordering Afghanistan, an official said.

The body of the man, named as Maulvi Salahuddin, was found dumped near a drain with a note saying that he was a "US spy", residents said.

Separately a man named as Jan Mohammad, 40, was shot dead in the troubled Bajaur district hours after Monday's airstrike that killed 80 people, another security official said requesting anonymity.

Residents said the victim was seen near the bombed madrassa in Chingai, a small town in Bajaur, talking on a satellite phone after the attack.

He also had a note left on his body accusing him of espionage. "We had suspicions that he had been working for US forces and the attack today confirmed that he was US spy," it said.

Residents said his family members refused to claim the body and very few people attended his funeral prayers.

At least half a dozen alleged spies for US forces in neighbouring Afghanistan have been killed in the semi-autonomous Pashtun tribal belt this year.