259 people held captive at an Islamic rehabilitation centre in the Nigerian city of Ibadan in Oyo State were rescued by security forces during a raid on Monday, a police spokesman said.
State police spokesman Fadeyi Olugbenga also said that the owner of the centre and eight other people were detained and an investigation launched.
According to Olugbenga some of the captives were chained.
The rescue of the victims is the latest in a series of raids by authorities in Nigeria in which at least 1,000 people have been released from similar facilities.
Last month, about 70 men and boys were rescued from a so-called Islamic school in Katsina State. The victims were chained and found to have been subjected to various inhuman and degrading treatments.
In September, more than 300 boys and men were rescued from a suspected Islamic school in the northern city of Kaduna.
Children, as young as five, were among the detainees who were allegedly sexually abused and tortured.
President Muhammad Buhari has come under pressure to rein in such centres which are common across the mostly Muslim north of Nigeria. The centres are unregulated facilities that allegedly offer rehabilitation services and usually an Islamic education.
In June, a statement by Buhari’s spokesman said the government intended to ban the schools. However, the statement added that a ban on such schools would follow due process and consultation with relevant authorities.