The attackers stormed Bethel Baptist High School in northwestern Kaduna state on July 5, abducting students who were sleeping in their dorms.
The kidnapping was the latest by heavily armed gangs, known locally as bandits, who have long plagued northwest and central Nigeria by looting, stealing cattle and kidnapping, but have lately targeted schools and colleges.
The 28 released students had been reunited with their parents after being released on Saturday, Joseph Hayab, the Bethel Baptist High School official.
“We were able to send out church buses to go to where the captors dropped them to pick them up,” he said.
In all, thirty-four of the kidnapped children were now free: five escaped earlier and one was released on health grounds, Hayab said.
Some money had been paid to the gang, he said, declining to say how much.
“The most important thing now is to get all the remaining children released,” he said.
– Rise in school kidnapping –
Kaduna state police were not immediately available for comment when contacted.
Of the five children who escaped on July 21, two were found by police and the other three made their own way back to the school, Hayab said.
“They escaped from the bandits when they were sent to collect firewood for cooking.”
After the kidnapping, the gang asked the school for food and a ransom to free the hostages.
Kidnappings of travellers on the roads or of influential people for ransom are common in Africa’s most populous country.
Boko Haram Islamists first kidnapped children from schools in 2014, when they took more than 200 girls from their dormitory in Chibok, causing a worldwide public outcry.
Abductions of schoolchildren have risen sharply since then, with around 1,000 students and pupils have been abducted across Nigeria since December.
Most have been released after negotiations by local officials with the organised criminal gangs.
Many though remain captive, including a hundred children abducted in early June from a Muslim school in the neighbouring state of Niger, and still held hostage.
“The Tegina boys and girls, some as young as five, have been in captivity for 56 long days now,” tweeted Nigerian analyst Bulama Bukarti on Sunday.
“It’s clear that parents have been left completely on their own, with both state and federal govt not making any concrete security or non-security efforts to free the helpless children.”
President Muhammadu Buhari, who is under fire for growing insecurity in the country, has ordered the security forces to ensure safe and early release of all kidnap victims.