The prison authorities in Gujarat has planned to instal high quality sensors in two central jails to alert officials about any underground movement and thwart bids by prisoners to escape by digging tunnels. The move comes five years after some prisoners dug up a tunnel in the British-era Sabarmati Central Prison here. "To foil attempts by inmates to escape by digging a tunnel, we have decided to install a 'tunnel detection system' in the Sabarmati central jail here and the Lajpore central jail in Surat district," Additional Director General of Police, Prisons, T SBisht told PTI. "Gujarat is probably the first state in the country which is planning to implement such a system injails," he claimed, adding that only the Border SecurityForce (BSF) uses it as of now to detect tunnels near border areas. The state government has allocated a budget of Rs 2.8 crore for the implementation of the project in these two jails, the official said. As a part of the system, several sensors will be installed about three meters under the ground at regular intervals inside the jail, Bisht said. "The sensor is capable of detecting underground vibrations and movements three metres up and down from the place where it is installed. Thus, it would cover a radius of six metres," he said. The sensors would transmit real-time signals on detecting any underground movement or vibrations due to the digging activity, according to the official. "The entire web of sensors will be connected to a control room and an alarm. Apart from activating the alarm on detecting vibrations, the system would also send an SMS to the designated numbers of jail officials about the underground activity," he said. The system is expected to be firstimplemented near the 'high security area' of Sabarmati jail by the end of this year, he said, adding that it would be installed in both the central prisons in Ahmedabad and Suratin a phase-wise manner. The jail's high security area is the place where hardened criminals and those accused in bomb blast cases are lodged. In March 2013, the prison authorities had found a 214-feet long tunnel inside the Sabarmati central jail. The authorities had then alleged that the tunnel was dug up by some of the accused in the 2008 Ahmedabad serial blasts case who were lodged in the jail.