A bomb exploded Monday at a boys' science secondary school in northern Nigeria, with dozens of students feared dead, Premium Times newspaper reported on its website, according to dpa. The attack occurred when students were lining up for a morning assembly at the boarding school in Potiskum, in Yobe state. "Many bodies of students are presently on the ground in pools of blood," a witness was quoted as saying. Premium Times reported that police confirmed the incident, without giving details.