Pakistani Taliban fighters beheaded a tribal cleric accused of being a U.S. spy in the Waziristan region bordering Afghanistan, a security official in the restive tribal region said.

The body of Maulana Salahuddin, 45, was found on Friday on a road between North and South Waziristan, two semi-autonomous regions regarded as hotbeds of support for al Qaeda and the Taliban fighting NATO, U.S. and Afghan forces across the border.

A note pinned to the cleric’s body described him as an American spy, the security official said. The corpse was sprayed with bullets after the beheading, he added.

Pakistan’s government signed a pact with tribal leaders in North Waziristan on September 5 to end clashes between pro-Taliban militants and Pakistani security forces.

Since the deal was reached, U.S. military officials say, attacks against U.S.-led NATO troops and Afghan government forces have tripled.

Pro-Taliban tribesmen appear to be violating the pact also by setting up a parallel administration in North Waziristan, just as they did after a similar treaty in South Waziristan.