A bomb exploded Monday during an assembly at Government Comprehensive Senior Science Secondary School, a boys’ science and technical school in Potiskum, in Nigeria’s Yobe State. Police say terrorist group Boko Haram is believed to be responsible for the attack, which was reportedly carried out by a suicide bomber disguised in a school uniform. The Associated Press said the death toll was at least 48 with some 119 injured. “The students had gathered for the morning assembly when something exploded in their midst with a thunderous sound at exactly 7:50 a.m.,” a teacher at the school told the BBC. A witness said parents were wailing at the sight of their ’s bodies. A local resident described “a mass of abandoned footwear and blood,” AFP reported. “We are still receiving casualties from the school, which is a stone’s throw from here,” said a medical worker on the scene. The governor of Yobe state said he would demand a full investigation.