Hundreds of boys at a Nigerian boarding school may be missing after an attack on the facility by gunmen, according to a report.

Gunfire could be heard for about an hour during the terrifying Friday night incident, in which the motorbike-riding bandits descended on the Government Science Secondary School in the Nigerian state of Katsina, shooting into the air.

More than 800 students live at the school, which is in the home state of Nigerian President Muhammadu Buhari. About 200 of the kids, who were able to escape, later returned. It’s unclear how many are still missing.

“I strongly condemn the cowardly bandits’ attack on innocent children at the Science School, Kankara,” Buhari said in a statement.

“Our prayers are with the families of the students, the school authorities and the injured.”

The school attack occurred just two days after the kidnapping of two dozen people from a village in the area.