Gunmen attacked a boarding school in northwestern Nigeria's Kaduna state on Sunday night.
Some 140 students were kidnapped, presumably to exchange them for ransom, a member of the school said.
"Attackers took 140 students with them, 25 managed to escape," details Emmanuel Paul, who teaches at the Bethel Secondary School boarding school.
Some 165 students were sleeping in the boarding school at the time of the attack.
Nigeria's Kaduna state has been regularly targeted by gunmen.
Since December, criminal gangs known locally as bandits have increasingly targeted schools and colleges for kidnapping attacks, hoping to squeeze ransom payments out of authorities.