According to sources, the last execution in the jail was carried out in 1995, that of a murder convict.
The capacity of the jail, which houses hardcore criminals, was put at 1,800 inmates during the British rule and was later increased to around 3,000.
Recently, the jail was in the limelight when suspected Indian Mujaheedin operative Qateel Siddiqui was killed inside the jail by fellow inmates, which allegedly led to the plotting of the August 1 serial bomb explosions in the city. The incident led to a big uproar, resulting in transfer of the jail superintendent.
The 'Operation X' carried out on Wednesday morning, was, however carried out with utmost secrecy, which caught the city by surprise.