Gunmen on Saturday released 42 people, including 27 students, who were kidnapped from a boarding school last week in the north-central Nigerian state of Niger, its governor said.

Twenty-seven students, three staff and 12 members of their families had been abducted last week by an armed gang who stormed the Government Science secondary school in the Kagara district of Niger state at around 2 a.m., overwhelming the school's security detail.

One boy was killed during the raid. "The Abducted Students, Staff and Relatives of Government Science Collage Kagara have regained their freedom and have been received by the Niger State Government," Governor Abubakar Sani Bello said in a tweet.

Kidnappings for ransom by armed groups, many of whom carry guns and ride motorcycles, are common across many northern Nigerian states. In a separate raid in Zamfara state on Friday, gunmen seized more than 300 girls in a raid on their school.