Police officers from the Oyo State Police Command on Monday raided an Islamic school located at Ojoo area of Ibadan, the state capital and freed 259 students who were being maltreated, an official has said.
The school is operated by Ismail Olore.
The Commissioner of Police, Shina Olukolu, who led his men to the scene of the incident, said he freed 34 females, 191 males, 11 children, "and 23 sick ones who were allegedly detained and chained for the past two to 10 years ago."
Mr Olukolu who addressed journalists at the school, said that four suspects have been arrested.
The Police Public Relations Officer in the state, Olugbenga Fadeyi, said the victims will be taken to 'reformation' centres in order to give them urgent medical attention.
"Oyo State government is involved in the evacuation process, and the police are currently investigating to unravel the incident," he said.
Meanwhile, the Commissioner for Women Affairs and Social Inclusion in the state, Fausat Sanni, said the situation was very pathetic but said: "the state government is currently on top of the situation".
Mrs Sanni said, "We got a distress call in our office this afternoon, and we came immediately to the scene of the incident. We have made arrangements to evacuate some of them to the hospital, as well as our correctional homes."
The Director of Ali Institute for Qur'an Memorisation, Ali Abdussalam, had earlier described some 'schools' in the city "claiming to be rehabilitation centres' as torture centres."
Mr Abdussalam, a former president (Amir), Muslim Students Society of Nigeria (MSSN), University of Ibadan, spoke during the graduation ceremony of the institute.
He said those centres "should not be linked to Islam because they (owners) do not have good motive before they (centres) were set up".
"That is why I said that we have a motive. The motive is to breed youth that will change the society for positive. If you observe those places that you just mentioned, you ask yourself, what kind of people established those places? They are people of questionable characters.
"And there is no way that you will be a teacher, when you have a wrong education, the students that you will teach will take after that your wrong education. That is what caused Boko Haram. You will see that they are giving the wrong education. This affected them."