bosaso somalia islamist al shabaab militants attack checkpoint somalia semi-autonomous puntland region kill least seven people early hours monday police say fighters ambush officer rush help colleagues outskirts city bosaso officer scene tell reuters al shabaab say take checkpoint leave though police say fight assault al shabaab launch string attack somalia capital mogadishu areas control federal government bid oust western-backed authorities impose group interpretation islamic law attack relatively rare puntland government security force patrol territory northeastern tip horn africa jut gulf aden arabian sea a.m. many well-armed al shabaab fighters attack us directions attempt capture checkpoint police captain abdifatah mohamed say three police four civilians die least 13 others wound clash say phone checkpoint abdiasis abu musab al shabaab military operation spokesman say fighters kill seven soldier wound 11 others capture bosaso checkpoint leave morning also ambush police reinforcement say puntland also home splinter group al shabaab swear allegiance islamic state security source say small contingent foreign fighters base militants attack checkpoint somalia 's puntland seven dead