Dozens of students at an Islamic seminary in western Nigeria who were abducted nearly three months ago and six of whom died in captivity have been freed, the school’s principal announced.

On May 30, about 200 heavily armed men invaded the town of Tegina, in Niger State (western Nigeria), and kidnapped 136 students from the private Muslim school Salihu Tanko.

Since December, Nigeria has suffered a series of mass kidnappings at schools and universities.

Six of the Tegina students died in captivity and 15 others managed to escape in June, according to the school’s management.

“The students have all been released. We are in the process of bringing them home,” principal Abubakar Alhassan told AFP. “I can’t give you an exact number now. We will have to examine them when we get home. But none of the students are in captivity.”

He did not provide details of the release or whether a ransom was paid.

A parent, Fati Abdullahi, whose 18-year-old daughter and 15-year-old son were among the abducted students, confirmed that her children were free.

“We got on the phone with those who brought them back. We followed their journey home,” he said, saying he was “looking forward to seeing them.

An emissary sent in early August by the parents to hand over a ransom of 30 million naira (61,000 euros) in exchange for the release of the children, had returned empty-handed. He himself had been held for a week because the kidnappers demanded more money, according to school officials.

Northwestern and central Nigeria have seen an increase in attacks, looting, and mass kidnappings by criminal gangs known locally as “bandits. But this year, gangs have begun targeting schoolchildren and students for ransom.

About 1,000 schoolchildren and students have been abducted since December, when gangs began targeting schools. Most have been released after negotiations, but hundreds remain trapped in camps hidden in the forests.

Bandits who abducted about 100 students from a Baptist high school in the northwestern state of Kaduna in early July have released 15 of their prisoners after obtaining a ransom, a family representative said Sunday.