March 10 (UPI) -- The U.S. Department of Defense estimates that about 140 U.S. troops have been wounded since the United States began its military operation against Iran last month. The injuries are in addition to seven U.S. service members who have been killed in retaliatory strikes by Iran. Pentagon spokesperson Sean Parnell said in a statement that a "vast majority" of those wounded have suffered "minor" injuries. Of about 140 injured, 108 returned to duty. "Eight service members remain