A video footage shows a moving car dragging a traffic policeman after he tried to stop the car for its rule-breaking act. [Photo from Weibo]

China's public security authorities have vowed to crack down on any act that violently interferes with the law enforcement ability of police after a traffic policeman was killed by a driver who was reportedly in violation of traffic laws in Shanghai.

The traffic management bureau of the Ministry of Public Security made the announcement on Thursday.

The tragedy happened when a 32-year-old policeman surnamed Mao was trying to stop a car when it took a left turn from a wrong lane at an intersection in Shanghai on Wednesday.

The car suddenly started to speed up while Mao was holding onto the car door, dragging the officer for about 10 meters.

Mao's head struck the ground and he later died of a brain hemorrhage.

The traffic management bureau sent condolences to the victim's relatives and ordered relevant authorities to ascertain facts as to the driver's criminal responsibility.

It also called on the public to cooperate with traffic police's law enforcement activities and obey all traffic laws.