Nigeria Katsina State Police rescued 67 people detained, tortured and inhumanly treated in a building called an Islamic "school".

"During the investigation, these 7 to 40-year-olds were discovered while in chains. The victims were also subjected to cruel and inhumane treatment," said Sanusi Buba, a Kusina state police spokesman in western northern Nigeria, said on October 14.

The raid began on October 12 in Sabon Garin in the Daura area of Katsina state. Police on October 14 said they were assisting the victims to reunite with their families.

The raid in Katsina, the home state of President Muhammadu Buhari, took place less than a month after about 300 people were rescued from a similar facility in the nearby city of Kaduna, where the victims also reported being abuse and torture.

Lawal Ahmad, a 33-year-old detained here, said he had witnessed sexual assaults, beatings and even the deaths of other victims over the course of two years. "They beat us, abused us and punished us every day in the name of teaching us," Ahmad said.

Police arrested Mallam Bello Abdullahi Umar, 78, the owner of the "torture house", hiding under the Islamic school.

"The way he treats the children is completely non-Muslim. We are very upset, they are being treated illegally," said Lawai Musa, a small merchant living near the area. Musa added many families have sent adult men or teenage boys here because they believe it is an Islamic teaching institution, which helps them improve their personality and increase their religious beliefs.