Gunmen from a criminal gang kidnapped 25 people and killed a staff member in an early morning raid on a northwestern Nigerian girls’ secondary school on Monday, police said.

The latest attack comes more than a decade after nearly 300 girls were abducted from Chibok in the restive northeastern region and sparked international outcry.

Since then, there has been a string of other abductions involving school children.

Police on Monday said the gang, armed with “sophisticated weapons, shooting sporadically, stormed the Government Girls Comprehensive Secondary School” in Kebbi state at about 4:00 am (8pm PKT).

Police were deployed, but “unfortunately, the suspected bandits had already scaled through the fence of the school and abducted twenty-five students from their hostel to an unknown destination,” police said in a statement.

The school deputy head was shot dead while a security guard was injured during the attack, according to a report prepared for the United Nations.

The military, police tactical units and local vigilantes have “been deployed in the area and they are currently combing the bandits’ routes and nearby forest” in a bid to rescue the abducted students and arrest the gangs, police said.

Nigeria’s northwest has for years been seeing a rise in heavily armed criminal gangs known as “bandits” who steal cattle, raid villages, kidnap and kill residents and loot and burn homes.

The northwest has become the region most affected by kidnappings. Africa’s most populous country has also been plagued by armed violence since the 2009 emergence of the Boko Haram group in the Lake Chad basin, in the northeast of the country.

The kidnapping of 276 schoolgirls from the town of Chibok on April 14, 2014, made headlines around the world. Almost 100 of the captives remain missing. More than 130 schoolchildren were kidnapped by gunmen in March last year in Kuriga, in another northwestern state of Kaduna. They were later released unharmed.

Data on kidnapping in Nigeria is unreliable mainly due to under-reporting, but according to a report last year by the charity Save the Children, more than 1,680 pupils were kidnapped in Nigerian schools from early 2014 to the end of 2022.

As the country grapples with security challenges on several fronts, hostage-taking has spiralled into a nationwide industry and become a favoured tactic of bandit gangs and jihadists.

In the northwest, authorities have tried to negotiate with bandits, striking peace deals and deploying vigilante groups.

But they have had little success, and critics say the kidnapping crisis is out of control.