According to eyewitnesses, quoted by the Daily Express, the car was in the middle of the rally when a passenger opened the door to shout at the protesters, which was then followed by the driver accelerating.

Several people were overthrown and at least four were injured as a result of a car that drove into yellow vests protesters in the French city of Rouen, BFM TV reported, citing a police source. As the broadcaster specified, first aid to those injured was provided immediately.

According to the media outlet, several people were inside the car that was blocked by the rally. The Daily Express reported that, citing eyewitnesses, the driver sped up after a passenger initiated a verbal exchange with protesters.
The driver left the scene and went to the police, BFMTV reported.

Source: sputniknews.com