Police arrested four of the attackers, who also fired five shots at them in the incident last night although none of the bullets found their target. The other assailants managed to flee in their car.
The arrested persons have been identified as Anil, Arvind, Sanjay alias Sanju and Kamal.
"The attackers fled after snatching a service revolver from a policeman and even hit Head Constable Rajinder with their car. Rajinder's condition is said to be critical and he is in ICU. His colleagues, constable Dinesh, Shishram and Amit were also injured in the attack," police said.
The group thrashed the policemen and even fired five shots at them, one from a pistol and four from a country-made revolver.
Meanwhile, a general patrol team reached the spot and managed to catch four of the assailants. One pistol and a country-made revolver was recovered from them.