A schoolgirl who was abducted with 24 others from a dormitory in northwestern Nigeria has escaped and is safe, said the school's principal, as hunters joined security forces in the search for the missing students in forests close to the school.

The girls were kidnapped before dawn on Monday, when gunmen attacked the dorm at the Government Girls Comprehensive Secondary School in Kebbi state's Maga town. Local police said the gunmen scaled the fence to enter the school premises and exchanged gunfire with police officers before seizing the girls and killing a staff member.

No group has claimed responsibility for taking the girls, but analysts and locals say gangs of bandits often target schools, travellers and remote villagers in kidnappings for ransoms. Authorities say the bandits are mostly former herders who have taken up arms against farming communities after clashes between them over strained resources.

Mass school kidnappings are especially common in northern Nigeria, and the Kebbi school is close to conflict hot spots including Zamfara and Sokoto states, where several gangs are known to operate and hide out.

The student who escaped arrived home late Monday, hours after the kidnapping, according to the school principal Musa Rabi Magaji. Another student was able to escape the gunmen in the minutes after the raid and was not abducted, the principal told AP.

“They are safe and sound,” Magaji said.

Meanwhile, security forces and hunters have intensified efforts to find and rescue the others. Security teams swept nearby forests where gangs often hide while others were deployed along major roads leading to the school.

Governor of Kebbi Nasir Idris visited the school on Monday and assured of efforts to rescue the girls, and Nigeria's Chief of Army Staff lieutenant general Waidi Shaibu met with soldiers in the hours after the attack and directed “intelligence-driven operations and relentless day-and-night pursuit of the abductors,” according to an army statement.

“We must find these children. Act decisively and professionally on all intelligence. Success is not optional,” the army chief said. (AP)