Heavily-armed gangs, known locally as bandits, have long plagued northwest and central Nigeria by looting, stealing cattle and abducting for ransom, but they have lately targeted schools and colleges.
On July 5, gunmen stormed Bethel Baptist High School in northwestern Kaduna state and abducted 121 students.
Kaduna police spokesman Mohammed Jalige told AFP that one of the students was freed 10 days ago and two more were released on Wednesday.
“They are now in our medical facility undergoing medical checks,” he said.
The students had been freed on health grounds, he said.
“It is obvious they have some health challenges, having spent weeks in captivity in the bush.”
A school official, Reverend Joseph Hayab confirmed the release of the first boy, whom Jalige identified as Abraham Aniya.
“He was extremely sick, so they decided to release him,” Hayab said.
The kidnappers had demanded food and ransom for the release of the hostages, but it was not immediately clear if any money changed hands to secure the release of the three.
Around 1,000 students and pupils have been abducted across Nigeria since December. Most have been released after negotiations with local officials, although some are still being held.
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.