Radical Islamist group Boko Haram – also known as the Islamic State of West Africa – has claimed responsibility for the kidnapping of more than 330 students in Nigeria.

The group abducted the schoolboys from the Government Science Secondary School in Kankara during an attack late last week. The attack was the largest such attack in recent years.

“The kidnappers had made contact and discussions were already on, pertaining to the safety and return of the students,” a spokesman for Nigerian President Muhammadu Buhari told reporters.

Local media outlet The Daily Nigerian claimed to have received a message from Boko Haram leader Abubakar Shekau. The news outlet said that Boko Haram attacked the school because it was teaching “Western Education,” which is against the tenets of Islam.

Students who were able to evade capture during the attacks said that hundreds of them were able to escape once the police fired on the armed rebels. Some students were also able to run away when they were forced to walk to a nearby forest, witnesses said.

There were more than 600 students at the Government Science Secondary School when the attack happened. Police immediately responded to the attack, which resulted in a gunfight between the heavily armed men.