KABUL, Afghanistan — The Afghan man who was killed in a U.S. drone strike last month was an enthusiastic and beloved longtime employee at an American humanitarian organization, his colleagues say, painting a stark contrast to the Pentagon’s claims that he was an Islamic State group militant about to carry out an attack on American troops.

Signs have been mounting that the U.S. military may have targeted the wrong man in the Aug. 29 strike in Kabul, with devastating consequences, killing seven children and two other adults from his family. The Pentagon says it is further investigating the strike, but it has no way to do so on the ground in Afghanistan after the Taliban takeover, severely limiting its ability to gather evidence.