A 17-year-old boy has been arrested on suspicion of attempted murder. The arrest occurred after three people were assaulted with a sharp object at a secondary school in northern England, police said Wednesday. Two adults and a child were treated for minor injuries but did not need to be transported to a hospital, according to The Birley Academy. The school, formerly known as Birley Community College, was closed for the rest of Wednesday. The school is located in the area. The suspect was in custody.