Nigerian police have released 259 people held captive at an Islamic rehabilitation centre in the south-western city of Ibadan, a police spokesman said on Tuesday.

Oyo state police spokesman Fadeyi Olugbenga said the facility was raided on Monday. “Yesterday, 259 persons were released,” he said, adding that they were locked in a building and some were chained.

He said nine people including the owner had been arrested and were under investigation.

More than 1000 people have been released from such centres in Nigeria in the last few weeks. However, the others have been in the predominantly Muslim north of the country, rather than the southern states that are mostly inhabited by Christians.

The raid will increase pressure on President Muhammadu Buhari to take action on loosely regulated centres that offer rehabilitation services and often an Islamic education. He has already called on police to shut down such centres.