The gate to this hospital in Kunduz remains closed... after the U.S. military admits it may have bombed it. The hospital is run by the medical aid group Doctors Without Borders. Officials say at least nine people have been killed and 37 wounded. Many patients and staff remain missing... officials say the attack happened at a time when almost 200 patients and employees were in the hospital. The incident, which is under investigation, could renew concerns about the use of U.S. air power in Afghanistan, a controversial issue in America's longest war. Fighting has raged around Kunduz, as government forces backed by American air power are attempting to drive out Taliban militants. Despite government claims to have taken control of the area, a bitter contest with the Taliban continues.