UN chief has added his voice to the kidnapped Nigerian girls early Friday. He demanded the "immediate" release the Nigeria schoolgirls.

Zamfara police confirmed that 317 school girls have been abducted by armed bandits, adding that the search for the students is on.

The schoolgirls were taken from their hostels by gunmen who raided the Government Girls' Secondary School in the town of Jangebe, a high-ranking government official with knowledge of the incident told CNN.

A police officer was killed in the attack, according to the source, who did not want to be named as he did not have permission to speak on record.

"They came on about 20 motorcycles and they marched the abducted girls into the forest," the source said. "The bandits arrived around 1.45 a.m. and they operated 'til about 3 a.m.."

"The sad part is that there's a military checkpoint that is about four minutes away from the school," he added.

About 500 students are normally at the boarding school, of whom around 315 were taken by the gunmen. Others managed to flee and return to their hostels, the source said.

(With input from agencies)