A bomb has gone off at a school assembly in the north-east Nigerian town of Potiskum, residents say, with unconfirmed reports of casualties.
The explosion happened at an boys' science and technical school in the town.
Militant group Boko Haram is likely to be blamed for the attack.
It has often targeted schools during its five-year campaign to establish an Islamic state, which has left thousands dead.
Entities 0 Name: Potiskum Count: 1 1 Name: Boko Haram Count: 1 Related Keywords 0 Name: north-east Score: 10 1 Name: potiskum Score: 10 2 Name: five-year Score: 10 3 Name: schools Score: 10 4 Name: town Score: 8 5 Name: haram Score: 8 6 Name: boko Score: 8 7 Name: nigerian Score: 7 8 Name: unconfirmed Score: 7 9 Name: casualties Score: 5 Authors Media Images 0
