Eight inmates of Agodi Prison in Ibadan, Oyo State, southwest Nigeria, were killed and 18 injured including prison officers Tuesday during an attempted jail break, the state's Controller of Prisons, Maureen Omeli said, according to dpa. Four prison officers were seriously injured during the incident, which was put down by the police. The casualties occurred when prison authorities invited in police to stop the jail break attempt, she explained. Agodi Prisons, built to house 500 inmates, had 680 inmates, comprising 619 Awaiting Trial Persons and 61 convicted inmates at the time of the attempted jail break, she said. Conducting newsmen round the vandalised prisons cells and other properties, Omeli said the inmates had protested against poor medical facilities and the alleged death of one inmate who was taken to a hospital at the weekend because of poor medical facilities at the prison. The riot started when prison officials were counting the inmates before handing over officers on the next shift when inmates overpowered prison warders as they opened the cells. Omeli said the inmates, who were armed, held the officials hostage for an hour before police intervened. "From preliminaries reports, the inmates believed there was no adequate medical care for them and importantly they thought one of them who was hospitalised last weekend was dead. That was why they revolted and damaged properties and attempted to escape after over- powering the officials," Omeli said. The police commissioner in Oyo state, Udom Ekpoudom, said: "There was an attempted jail break and the police were invited and we stopped it and if they had escaped, the prison authorities and the police would have been in trouble. "They destroyed properties, injured prison staff and drilled holes into the walls with the attempt of escaping, but none of them escaped," Ekpoudom said.