More than 400 inmates may face charges over the riot, a source said yesterday. The source said prosecution action might not just be confined to the 30 to 70 hardcore troublemakers initially identified. 'It's now possible that all of the more than 400 inmates involved will be charged with rioting,' he said. Twenty-seven inmates identified as hardcore rioters have been transferred from the minimum-security jail to the maximum-security Lai Chi Kok Reception Centre for further questioning. They are likely to be the first batch of inmates facing rioting charges, such as arson, criminal damage and assault. Dozens more inmates identified by disciplinary officers as having been heavily involved in the rampage have been segregated from the remaining inmates at the centre. Marine regional crime unit superintendent Poon Kit-sang said whether all the 433 local inmates would be charged depended on available evidence. 'If there is evidence to prove that anyone has committed a criminal offence, we'll seek legal advice from the Department of Justice to take prosecution action,' he said. The minimum-security centre is not equipped with closed-circuit television so police will have to base their investigation on the more than 500 disciplinary officers who helped quell the violence. Security has been tightened at the centre and inmates have to ask officers to light cigarettes for them after matches were confiscated. It is understood that Correctional Services management has asked all prison chiefs to stay alert for minor disputes among inmates.