A key anti-Taliban leader in northwest Pakistan was assassinated and three others wounded in a bomb attack on Friday after they said prayers for a major Muslim festival, officials said. Shahpoor Khan led a tribal militia against Taliban insurgents in the Mamoond district of Bajaur. He was killed while returning home at the start of the Eid al-Adha festival when an improvised explosive device went off in his hometown of Badan, local administration chief Jamil Khan said. "The tribal leader was killed on the spot and his colleagues were seriously wounded in the blast," the official said. Khan had been returning home after saying special Eid prayers in a mosque. Some people in Bajaur, which borders Afghanistan, celebrate the start of the festival one day ahead of the festivities in Pakistan, the official said. Khan, who was in his 40s, was the successor to Malik Rehmatullah who was killed in a suicide attack at a mosque last year along with around 20 people.