Two U.S. Army soldiers were killed in combat operations and another died in a non-combat incident, the military said Sunday, according to The Associated Press. An explosion in the Salahuddin province northwest of Baghdad killed the solider and injured another on Sunday. Both were assigned to Task Force Lightning. Southwest of Baghdad, a roadside bomb killed a soldier and injured two others assigned to Multi-National Division-Baghdad, the military said. Another soldier with Task Force Lightning died in a non-combat related incident, which is currently under investigation, the military said. No other details were given. The names of the soldiers were not released pending notification of relatives.