Taliban commander Fazal Mehsud was arrested when the Crime Investigation Department raided a house in Kemari area of Karachi.
A cache of weapons, including Kalashnikovs, grenades and ammunition, was found in the house, TV news channels quoted officials as saying.
Media reports said Fazal Mehsud was considered a close aide of Tehrik-e-Taliban Pakistan commander Baitullah Mehsud, who was killed in a US drone attack in the country's restive tribal belt two years ago.
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