GURUGRAM: An undertrial prisoner at Bhondsi jail was beaten up and stabbed inside the premises on Tuesday morning, police said. Five undertrial prisoners were booked in connection with the incident. According to a jail official, at 10.50am on Tuesday, Bharat, Vijay, Mohit, Rahul and Mahipal attacked Lyon with a sharp object. Jail warden Surat intervened in the fight, rescued Lyon and took him to the prison hospital. The prisoner was then referred to Civil Hospital in Sector 10. Deputy superintendent of the jail, Charan Singh said, “The reason behind the attack is not known.” An FIR was filed under sections 323 (causing hurt), 324 (stabbing), 148 (rioting), 149 (unlawful assembly) of IPC at Bhondsi police station.