(AP) -- More than 300 schoolboys abducted last week by armed men in northwest Nigeria have been released, a government official said Thursday. In an announcement on Nigerian state TV, NTA, Katsina State Gov. Aminu Bello Masari said the 344 boarding school students were turned over to security officials and were being brought to the state capital, where they will get physical examinations before being reunited with their families. "I think we can say ... we have recovered most of the boys, if not all of them,” Masari said. He did not disclose if the government paid any ransom. President Muhammadu Buhari welcomed their release, calling it “a big relief to their families, the entire country and to the international community,” according to a statement from his office. Amid an outcry in the West African nation over insecurity in the north, Buhari noted his administration's successful efforts to secure the release of previously abducted students. He added that the government "is acutely aware of its responsibility to protect the life and property of the Nigerians.” “We have a lot of work to do, especially now that we have reopened the borders," Buhari said, acknowledging that the Northwest region "presents a problem” the administration "is determined to deal with.” Boko Haram claimed responsibility for last Friday's abduction of the students from the all-boys Government Science Secondary School in the Katsina State village of Kankara. The jihadist group carried out the attack because it believes Western education is un-Islamic, factional leader Abubakar Shekau said in a video earlier this week. More than 800 students were in attendance at the time of the attack. Hundreds escaped, but it was believed that more than 330 were taken. For more than 10 years, Boko Haram has engaged in a bloody campaign to introduce strict Islamic rule in Nigeria’s north. Thousands have been killed and more than 1 million have been displaced by the violence. The group has been mainly active in northeast Nigeria, but with the abductions from the school in Kankara, there is worry the insurgency is expanding to the northwest. The government had said it was negotiating with the school attackers, originally described as bandits. Experts say the attack was likely carried out by local gangs, who have staged increasingly deadly assaults in northwest Nigeria this year, and could possibly have been collaborating with Boko Haram. Armed bandits have killed more than 1,100 people since the beginning of the year in the region, according to Amnesty International. Parents of the missing students have been gathering daily at the school in Kankara. News of the students' release came shortly after the release of a video Thursday by Boko Haram that purportedly showed the abducted boys. In the more than six-minute video seen by Associated Press journalists, the apparent captors tell one boy to repeat their demands that the government call off its search for them by troops and aircraft. The video circulated widely on WhatsApp and first appeared on a Nigerian news site, HumAngle, that often reports on Boko Haram. Usama Aminu, a 17-year-old kidnapped student who was eventually able to escape, told the AP that his captors wore military uniforms. He said he also saw gun-toting teens, some younger than him, aiding the attackers. He said the kidnapped boys tried to help each other as bandits flogged them from behind to get them to move faster and forced them to lie down under large trees when helicopters were heard above. Aminu escaped at night. He was able to return home after being found by a resident in a mosque who gave him a change of clothes and money. Government officials said earlier this week that police, the air force and the army tracked the kidnappers to a hideout in the Zango/Paula forest. Katsina state shut down all its boarding schools to prevent other abductions. The nearby states of Zamfara, Jigiwa and Kano also have closed schools as a precaution. Subscribe to our YouTube channel: https://bit.ly/2TwO8Gm Bloomberg Quicktake brings you live global news and original shows spanning business, technology, politics and culture. Make sense of the stories changing your business and your world. To watch complete coverage on Bloomberg Quicktake 24/7, visit http://www.bloomberg.com/qt/live, or watch on Apple TV, Roku, Samsung Smart TV, Fire TV and Android TV on the Bloomberg app. Connect with us on… YouTube: https://www.youtube.com/user/Bloomberg Breaking News on YouTube: https://www.youtube.com/c/BloombergQuickTakeNews Twitter: https://twitter.com/quicktake Facebook: https://www.facebook.com/quicktake Instagram: https://www.instagram.com/quicktake