About 140 students are missing after armed men raided a boarding school in Nigeria’s Kaduna state on Monday, and police said they were in hot pursuit alongside military personnel.

The attack is the 10th mass school kidnapping since December in northwest Nigeria, which authorities have attributed to armed bandits seeking ransom payments.

Police said gunmen shooting wildly attacked the Bethel Baptist High School in the south of Kaduna state overnight.

“They … overpowered the school’s security guards and made their way into the students’ hostel where they abducted an unspecified number of students into the forest,” a police statement said, adding 26 people including a female teacher had been rescued.

Reverend John Hayab, a founder of the school, told Reuters news agency about 25 students had managed to escape.

Roughly 180 students attended the school and were in the process of sitting exams, according to Hayab, whose 17-year-old son escaped, and parent, Hassana Markus, whose daughter was among those missing.

Local residents who declined to be identified said security officials cordoned off the school after the attack, which took place between 11pm on Sunday and 4am on Monday.

“The kidnappers took away 140 students, only 25 students escaped. We still have no idea where the students were taken,” Emmanuel Paul, a teacher at the school told AFP news agency.

Kaduna state police spokesman Muhammed Jalige confirmed the attack, but could not give details on the number of pupils taken.

“Tactical police teams went after the kidnappers,” he said. “We are still on the rescue mission.”