Bharti's gang, also referred to as the Kranti Gang, was mostly active in Haryana, but in the last one year, they had carried out crimes in Delhi.
One of the criminals, Kapil, who was injured, is currently undergoing treatment at the AIIMS Trauma Centre. His condition is serious, police said.
Of the eight injured policemen, six had suffered bullet injuries.
The condition of three policemen was critical. They are now stable and under observation. The rest are hospitalised and undergoing treatment, police said.
The case is being investigated by the south district police and officials are recording statements of witnesses, they said.
The police's Special Cell had been tracking the gang for the last six-seven months. Yesterday, it was learnt that the gang members would be coming to Chandan Hola village in Chhatarpur, and a team of the cell's Northern Range, comprising 30 police personnel, was stationed on the route they were expected to take while leaving from a farmhouse, where they had assembled.
Officers are waiting for Kapil's condition to improve so that they can ascertain the identity of the others who were accompanying him and the reason for which they had gathered at the farmhouse, police said.
The farmhouse owner, Sanjeev, is still at large.
They are questioning Hyundai dealers in the National Capital Region to identify the car's owner.
According to investigators, they had found 40 fake numberplates from the car.
Those killed in the encounter have been identified as gang chief Bharti, Vidroh, Umesh Don and Bhiku, the police said.
Bharti and Vidroh were carrying rewards of Rs 1 lakh each, while Umesh a reward of Rs 50,000. They were accused in cases of murder and extortion, they said.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)