Pakistan's army said it had killed a top aide of fugitive Swat Taliban commander Maulana Fazlullah, as they continued their hunt for militant chieftains in the northwest valley. A spokesman for the army said Nisar, also known as Ghazi Baba, was killed in a clash just outside Swat's main town Mingora today. He said Nisar was killed in an encounter and his was arrested by the security forces. He was one of the 15 Swat insurgents commanding a 10 million rupee bounty offered by the authorities in May. The Swat Taliban was not immediately available to confirm the death, but residents in Matta said they had seen Baba's corpse.