Nigerian gunmen have released about 100 students abducted on May 30 from a Quranic school in Tegina, Niger state, according to the school's director.

In a telephone interview with France 24, the director said that all the students have been released and are now being returned to their homes.

"I can’t give you an exact number now. We will have to examine them when we get home. But none of the pupils is in captivity,” the director states. 

He did not give any details of how the students were released.

Northwestern and central Nigeria are witnessing an increase in attacks, looting, and kidnappings, which are carried out by criminal gangs known locally as Bandits.

Greed appears to be driving the kidnappings more than ideology, but analysts are concerned about a possible alliance between these criminal groups and Boko Haram and ISIS in West Africa.

Gunmen abducted 140 high school students in Kaduna state on July 5, their fourth operation in as many months, and transported them to unidentified locations.

According to Nigerian authorities, at least 22 people were killed in an attack alleged to be by an armed group targeting a caravan of Muslim pilgrims in Plateau state, central Nigeria, a few days ago.