Police in northwest Nigeria said 317 students were abducted by gunmen on Friday in the country's latest mass kidnapping, and a rescue operation was underway.
"The Zamfara State Police Command in collaboration with the military have commenced a joint search and rescue operations with a view to rescuing the 317 students kidnapped by the armed bandits in Government Girls Science Secondary School Jangebe," police spokesman Mohammed Shehu said in a statement.
Heavily-armed criminal gangs known locally as "bandits" in northwest and central Nigeria have stepped up attacks in recent years, kidnapping for ransom, raping and pillaging.
President Muhammadu Buhari said on Twitter "We will not succumb to blackmail by bandits and criminals who target innocent school students in the expectation of huge ransom payments."
"Let bandits, kidnappers and terrorists not entertain any illusions that they are more powerful than the government," he added.
"They shouldn't mistake our restraint for the humanitarian goals of protecting innocent lives as a weakness or a sign of fear or irresolution."
Just last week, 42 people were taken by a gang from a boys school in nearby Niger state.
In December, more than 300 boys were kidnapped from a school in Kankara, in President Muhammadu Buhari's home state of Katsina, while he was visiting the region.
The boys were later released but the incident triggered outrage and memories of the kidnappings of schoolgirls by jihadists in Dapchi and Chibok that shocked the world.
A parent told AFP he had received a call about the latest incident in Zamfara.
"I'm on my way to Jangebe. I received a call that the school was invaded by bandits who took away schoolgirls. I have two daughters in the school," said Sadi Kawaye.
Police have not yet confirmed the incident.
Kidnappings are just one security challenge facing Africa's most populous country, where militants are waging a jihadist insurgency in the northeast and ethnic tensions are simmering in some southern regions.
Northwest and central Nigeria have increasingly become a hub for large criminal gangs who raid villages, killing and abducting residents after looting and torching homes.
Bandits operate out of camps in Rugu forest, which straddles Zamfara, Katsina, Kaduna and Niger states.
Nigerian armed forces are deployed there but attacks and mass kidnappings persist.
The gangs are largely driven by financial motives and have no known ideological leanings.
But there are concerns they are being infiltrated by jihadists who are fighting out a decade-old conflict that has killed more than 30,000 people and spread into neighbouring Niger, Chad and Cameroon.