The victim, identified as Milan Sharma (22), was heading towards the bank in his scooter when a motorbike hit him from behind and he fell on the road.
Later, one of the bikers allegedly threw a handful of red chilly powder on Sharma's face and fled after taking away the bag containing cash, said a police official.
A case has been registered and the police are trying to ascertain the identity of the robbers, the official added.