Holi revellers injured two policemen at Shimla's Ridge Ground on Thursday, officials said.
Drunk revelers were abusing while celebrating Holi when policemen on duty stopped them from doing so, Deputy Superintendent of Police, Shimla, Pramod Shukla said.
The men attacked the policemen and two of them were injured, the DSP told news agency PTI.
He said one constable was critically injured.
The police have mentioned some of the suspected persons but they are yet to be formally arrested as the matter is being investigated, he added.
There was huge rush at Ridge Ground at the time of the incident which has made it difficult to identify the persons involved in the attack, he added.
A case was registered under sections 353 (assault or criminal force to deter public servant from discharge of his duty), 332 (voluntarily causing hurt to deter public servant from his duty), 147 (rioting) and 149 (unlawful assembly) of the Indian Penal Code (IPC) at Sadar Police Station, he added.