Nigerian police freed 259 people held at an Islamic rehabilitation centre in Ibadan, police said, adding some complained of being beaten by their captors.
It was the latest in a series of raids on Islamic institutions in Nigeria in recent weeks. More than 1 000 people, many of them children, have been rescued.
Captives said they were physically and sexually abused and chained to prevent escape.
The raids are increasingly embarrassing for President Muhammadu Buhari, a Muslim who called on police to crack down on such centres.
Other sites raided in police operations have been in the mostly Muslim north. Ibadan is in the south mostly Christian.
Oyo state police spokesman Fadeyi Olugbenga said the facility was raided on Monday.
“Yesterday, 259 persons were released. We had women, men and teenagers,” Olugbenga said. Some were locked in a building and some were chained.
Images from local TV station TVC taken after the captives were released showed mostly young men and teenage boys. An infant was in the group. Many were emaciated.
“We eat a meal a day,” one man told TVC.
According to Olugbenga, nine people including the rehabilitation centre owner were arrested and under investigation.
Spokesmen for the president and vice president declined to comment.
The president’s office issued a statement in October saying “no responsible democratic government would tolerate the existence of torture chambers and physical abuse of inmates in the name of rehabilitation”.
At other raided facilities, some parents thought their children were there to be educated and even paid tuition fees. Others sent misbehaving relatives to Islamic institutions to instil discipline.