Six persons were fleeing after robbing over Rs 65,000 at gun point from Guru filling station in Bhamaura village last night when the constables rushed to the spot, police said.
The accused opened fire, prompting the policemen to fire in self defense, killing two of them, they said, adding that the remaining four managed to escape with the cash.
A manhunt has been launched to nab the remaining four accused, they said.