NEW : Kenyan and Somali governments pledging cooperation in Al-Shabaab fight . NEW : David Tebbutt was shot dead while trying to resist the attack . U.S. military says it has killed a top leader of the Islamic extremist group Al-Shabaab. The move of Kenyan troops comes after threats from Al-Shabaab to enter Kenya .
NEW : Kenyan and Somali governments pledging cooperation in Al-Shabaab fight . NEW : U.S. military says it has killed a top leader of the Islamic extremist group Al-Shabaab. The move of Kenyan troops comes after threats from Al-Shabaab to enter Kenya .