Disguised in a school uniform, a suicide bomber set off explosives hidden in a backpack during an assembly Monday at a high school in northern Nigeria, killing at least 48 students and wounding 79 others.
It was the latest attack by suspected Boko Haram terrorists who kidnapped more than 200 schoolgirls earlier this year.
Monday’s bombing came one week after a suicide attack in Potiskum, the capital of Yobe state, killed 30 people taking part in a religious procession by moderate Muslims.
Survivors said the bomber hid the explosives in a type of backpack popular with students.
Months ago Nigeria’s military reported finding a bomb factory where explosives were being sewn into backpacks in the northern city of Kano.
The U.S. strongly condemned the attack.
“Our sympathies and thoughts are with the victims and their families of these latest egregious assaults on innocent civilians by those bent on fomenting violence, extremism and insecurity in northeastern Nigeria and the region,” State Department spokeswoman Jen Psaki told reporters in Washington.