Troops `` overran a stiff resistance '' from Islamist militia , spokesman says . Score: 6 U.S. backs Somalia 's weak government , fears it could fall to al Qaeda-linked group . U.S. officials warn that Somalia could become haven for al Qaeda operatives .
Troops `` overran a stiff resistance '' from Islamist militia , spokesman says . But residents still report heavy fighting between Al Shabaab , pro-government forces . U.S. backs Somalia 's weak government , fears it could fall to al Qaeda-linked group . U.S. officials warn that Somalia could become haven for al Qaeda operatives .