Singh was injured on his right elbow and taken to the nearby hospital. He was released after primary treatment, a senior officer of Karaya Police Station said.
"The incident occurred at around 6.25 PM when the Bidhannagar CP's vehicle was moving on the northern flank of the Ma flyover," the officer said.
"Suddenly the vehicle in front of it screeched to halt following which the CP's driver used hard break. Almost at the same time a trailing vehicle, hit his car from behind causing injury to Singh," he said.