Police said the prisoners broke the tin ceiling of their cell and escaped through a hole in the fence of the gaol compound at around 2.30 AM.
The duo, who belong to local underground group Dima National Liberation Front, were identified as David Kemprai alias 'Action Dimasa' and Bongirson Khelma, police said, adding that they were incarcerated for indulging in anti-social activities.
A massive man hunt has been launched to track down the two prisoners and an inquiry is on into the incident.