A police head constable sustained injuries when he tried to stop two youths from attacking a man at Pettandur Agrahara in Whitefield police station limits around 12.30 am on Thursday.
The injured has been identified as P G Babu attached to Whitefield police station. Ravi, 22, and Nadeesh, 25, have been arrested.
Ravi and Nandeesh picked up a quarrel with local resident Munendra over a trivial issue and they tried to attack him with a knife.
Babu and another constable tried to stop the duo from attacking Munendra. In the melee, Babu sustained injuries on his hands.
Whitefield police have registered a case of attempt to murder.