A roadside bomb exploded outside a girl's school in northwest Pakistan on Wednesday, killing seven people, including three U.S. soldiers involved in training Pakistan's paramilitary Frontier Corps. A Frontier Corps member and three school girls were also killed. The blast injured 62 people, most of them school girls inside the building; 10 of the wounded are in serious condition. Police believe that the bomb, which exploded as a convoy of U.S. soldiers passed the school, was detonated by remote control. The attack took place in the mountainous Lower Dir area of northwest Pakistan, where Pakistani troops and Taliban militants fought fiercely during last summer's government offensive against insurgency in the area.