Police said that Sayyad Farooque, the accused, was arrested immediately.
After picking quarrel with Khanderao Solgir, a fellow policeman who was on duty then, Sayyad allegedly stabbed him this afternoon in the Hanuman chowk locality.
Solgir, who was grievously injured, died on the spot. The exact reason behind the assault was yet to be ascertained, police said.