washington u.s.-led coalition fight islamic state militants say friday confirm another 61 likely civilian deaths cause strike iraq syria raise 685 number civilians acknowledge kill since conflict begin coalition say statement july investigate 37 report civilian casualties find 13 report credible estimate 61 unintentional civilian deaths coalition investigate another 455 report civilian casualties cause artillery air strike statement say acknowledge least 685 civilian deaths due air artillery strike since conflict begin august 2014. deadly incident investigate july march 14 strike near mosul coalition attack islamic state position fighters fire coalition ally strike believe kill 27 civilians adjacent structure statement say u.s.-led force acknowledge kill 61 civilians iraq syria