More than 130 schoolchildren kidnapped by gunmen in northwestern Nigeria earlier this month were released unharmed on Sunday, officials and the army said. The mass abduction in Kuriga, Kaduna state on March 7 was one of the biggest attacks on a school in years and sparked a national outcry over insecurity.The army said the hostages were freed in the early hours during a rescue operation but did not provide details.Spokesman Major General Edward Buba shared photos of children wearing dust-covered uniforms in buses.”The rescued hostages totalling 137 comprise of 76 females and 61 males. They were rescued in Zamfara state and would be conveyed and handed over to the Kaduna state government for further action,” he said.Teachers and residents previously said around 280 pupils between the ages of eight and 15 were kidnapped when armed criminals, known in Nigeria as bandits, stormed the school on motorbikes.Discrepancies between the number of people kidnapped and released are common in Nigeria due to unclear early reports and the return of those who go missing while fleeing attacks.But it was not clear why there was such a large difference between the figures this time.Buba told AFP that “all the captives had been rescued”.He said no troops had been wounded but did not comment further, citing what he called the “ongoing operation”.- ‘Day of joy’ -President Bola Ahmed Tinubu welcomed the news and the “tireless dedication” of those who helped secure the children’s release. Tinubu has faced growing pressure after promising to tackle Nigeria’s many security challenges when he came to power last year.”The president assures Nigerians that his administration is deploying detailed strategies to ensure that our schools remain safe sanctuaries of learning, not lairs for wanton abductions,” his spokesman said.Bandit gangs routinely attack communities, loot villages and carry out mass kidnappings for ransom in northwest and north-central Nigeria.The gangs have targeted schools and colleges in the past, but there had been a lull in these attacks before the Kuriga abductions. Troops had been searching forests for the pupils and relatives said the kidnappers demanded a large ransom — but Tinubu insisted he had ordered security forces not to pay up.Kidnap victims in Nigeria are often freed following negotiations with the authorities, though a 2022 law banned handing over money to kidnappers and officials deny ransom payments are made.”The abducted Kuriga schoolchildren are released unharmed,” Kaduna state governor Uba Sani said in a statement that did not specify how they were freed.”This is indeed a day of joy,” he said, thanking “all Nigerians who prayed fervently for the safe return of the schoolchildren”.Sani had been expected to brief the media on Sunday but his address was delayed until Monday.- Wave of abductions -Nigeria has recently been hit by a wave of mass abductions and many victims across the country are still missing.Last weekend, kidnappers seized more than 100 people in two attacks in Kaduna state.On Saturday, the army said it had rescued 16 pupils kidnapped just days after the Kuriga attack from a school in Sokoto, also in the northwest.Hostage-taking has spiralled into a nationwide industry and some experts believe the country’s economic crisis is now driving a rise in kidnappings as desperate Nigerians turn to crime for income.Nigerian risk consultancy SBM Intelligence said it had recorded 4,777 people abducted since Tinubu took office in May last year.The mass kidnapping in Kaduna state and another in Borno state came almost 10 years after Boko Haram militants triggered a huge international outcry in 2014 by abducting more than 250 schoolgirls from Chibok in the northeast.