Suspected Islamic militants captured and beheaded an Afghan teacher whom they accused of being a spy for the United States, an official said Wednesday. The man's body was found early Tuesday in a large sack dumped by a road near Jandola, a town in the South Waziristan tribal district, the local security official said. He asked not to be identified due to the sensitive nature of his job. A note found with the beheaded man's body identified him as "Akhtar Usman, the one who spied for America," the official said. He said the forehead of the man's severed head was inscribed with the word for "hypocrite" in Urdu, Pakistan's main language.Usman, in his 30s, was a teacher at an Islamic school in nearby North Waziristan and was known to have spoken out against militants in the area, the official said.