Citing the incident of rampage by a group of inmates inside a prison in West Bengal's Hooghly district back in January, Chief Minister Mamata Banerjee on Tuesday noted that a lot of criminal activities takes place inside the prison there and asked police to take strong action against such incidents."A lot of mafia are operating from inside the prison in Hooghly. This must be taken care of. Some of them them are using gadgets like cell phone, laptop, computers, cameras inside the jail and they are contacting people outside to plan certain mischief. Such things must be kept under supervision," Banerjee said during the administrative meeting in Hooghly."The inspectors in charge of local police stations must handle these things strongly. If immediate action is taken on such incidents, the incidents would not be able to develop further," she said.Stating that creating ruckus inside the prisons have become a habit for the inmates in Hooghly, Banerjee asked the police officials concerned to conduct continuous monitoring to curb such incidents."We often receive news of disturbance from jails in Hooghly. This has become a habit. Whenever there is a lapse, such habits can creep in. If there is a continuous monitoring, such things would not happen," she added.A group of inmates, brought in from Kolkata's Presidency jail, fought a pitched battle with the jail wardens and injured four staffers inside Hooghly jail in January this year. The offenders also set fire on the jail furniture and hurled bricks at the staff.