kabul unite nations mission afghanistan say least 10 civilians may kill air strike northern city kunduz last week despite u.s. military investigation find civilian deaths series message twitter u.n. assistance mission afghanistan say interview multiple survivors medics elders others give strong reason believe civilians among victims saturday attack credible report least 10 civilians kill kunduz afghanistan air strike nov unama initial find show say statement contradict comment local afghan military officials well u.s. statement tuesday say investigation find evidence civilian deaths episode underline lack clarity report civilian casualties issue likely become increasingly prominent unite state step air strike taliban insurgent group captain tom gresback spokesman u.s. military say pentagon still stand previous statement find civilian deaths add u.s. force afghanistan examine consider credible evidence allegations civilian casualties present take allegations civilian casualties seriously take necessary step ensure mitigate loss civilian life visit kabul september u.s. defense secretary jim mattis say commanders would give great freedom use american firepower taliban everything humanly possible would do avoid civilian casualties former president hamid karzai clash bitterly unite state issue past years condemn air strike government president ashraf ghani far make public comment account local officials residents indicate many 13 people kill air strike chahardara district outside kunduz city afghan media report much high figure without independent confirmation afghan special force local provincial governor say 48 militants kill deny civilians kill recent report unite nations say 52 percent increase civilian casualties air strike first nine months year 205 kill 261 wound issue particular resonance kunduz 42 civilians kill u.s. air strike hospital run medical aid group medecins sans frontieres fight regain city taliban 2015. u.n. say believe afghanistan air strike kill civilians