KANO, Nigeria -- Gunmen who kidnapped more than 100 students from a school in northwest Nigeria more than two months ago released 10 more of the hostages after ransom payment, the head of a parents association said Sunday.

Assailants stormed Bethel Baptist High School on July 5 on the outskirts of Kaduna city, abducting 121 students who were sleeping in their dorms.

The Bethel abduction was one of a string of kidnappings by armed gangs known locally as bandits who terrorise northwest and central Nigeria, looting, stealing cattle and kidnapping.

The gangs have recently been targeting schools and colleges, seizing students to extract ransoms out of parents and authorities.

''The kidnappers released 10 more students today after we met their financial demand as with previous students they released,'' Joseph Hayab said, without saying how much was paid.

The latest release happened a week after 10 other students were freed.

''We now have 11 more students in captivity and we hope all will be released the next time we reach an agreement with the bandits,'' Hayab said.

The kidnappers have been freeing the abducted students in batches, which Hayab said was meant to extort more money from parents as money ''is paid everytime the students are released''.

So far 110 students have either been released or managed to escape.

Three of the captors have been arrested, national police spokesman Frank Mba said on Thursday.

More than 1,000 students and pupils have been abducted in the north since December, though most were released after negotiations.

Last month bandits freed 93 pupils abducted from an Islamic seminary in central Niger state after spending three months in captivity.