Eighteen inmates escaped Wednesday through a tunnel from a prison in the eastern Turkish city of Bingol, local governmental officials said.
Four of the inmates were reported to have been sentenced due to PKK case.
The inmates were staying at a M-type prison, where maximum 10 inmate-wards exist and houses a total of 325 inmates.
A tunnel was learnt to be 40 meter far from the prison wall, with 70 meter length and 65 centimeters width.
The inmates were reported to have changed their clothes at Kaleonu street of the city and left the scene of crime after getting out the prison.
A wide-range operation was conducted to find the inmates in nearby cities and districts.
Officials are seeking any external assistance related to the prison break which is estimated to have occurred at night.