Boko Haram has claimed responsibility for the mass abduction of students at Government Science Secondary School, Kankara in Katsina State last week.

In an audio tape released on Tuesday, Boko Haram leader, Abubakar Shekau said: “Our brothers were behind the abduction in Katsina.”

A large group of men armed with AK-47 riffles overran the all-boys college on Friday night and marched more than 300 students into the surrounding forests.

Boko Haram and its splinter faction, the Islamic State in West Africa Province (ISWAP), have for years waged a violent armed campaign in the northeast of the country as well as  neighbouring Cameroon, Chad and Niger.

Late on Monday, the governor of Katsina State, Aminu Bello Masari said the abductors “have made contacts with the government”.

“Talks are ongoing to ensure their safety and return to their respective families,” he said on Twitter.

A joint rescue operation was launched on Saturday by the Nigeria Police, the Air Force and Army, according to the government. The army said on Monday it had located the hideout of the men, and that a military operation was under way.