A Delhi Police constable, who is battling for life at the RML hospital, was among the 78 police personnel who were injured during the day-long protest at India Gate on Sunday.
Apart from the police personnel, 65 protesters also sustained injuries when police lathicharged and directed water cannons at the demonstrators to disperse them.
Senior police officers said the critically injured constable, identified as Subhash Tomar, lost his consciousness after suffering injuries during stone-pelting. But doctors at the RML hospital said Tomar apparently had a cardiac arrest.
"Constable Subhash Tomar is fighting for his life at Ram Manohar Lohia Hospital," said Taj Hasan, joint commissioner of police (central range). Tomar is posted at Karawal Nagar police station. He was beaten up at Tilak Marg near India Gate in the evening by "hooligans among protesters".
Dharmendra Kumar, special commissioner of police (law and order), said, "He is critical. He sank thrice but was revived by doctors. He is now on ventilator."
"When he was brought here, he was in a state of cardiac arrest. He was very critical and we performed cardiopulmonary resuscitation on him. He is presently in the Intensive Care Unit (ICU) and his condition is serious," said Dr TS Sidhu, medical superintendent of Ram Manohar Lohia hospital.
Among the 78 policemen injured were some senior officers such as joint commissioner (Central) Taj Hasan, additional commissioner (New Delhi) KC Dwivedi, deputy commissioner of police (Outer) BS Jaiswal and additional deputy commissioner (New Delhi) Sanjay Tyagi.
At least 25 vehicles - 12 DTC buses, 12 PCR vans and a Doordarshan vehicle - were damaged.