A pedestrian is being treated at the side of the road after a collision with a car in Folly Bridge, Oxford.
There are seven police cars and an ambulance at the scene and there are reports a man had to be restrained.
Thames Valley Police spokesman James Williams said as well as the collision, another man has been arrested on suspicion of assault at the same location.
He said: "It's not clear from the log at this stage whether the two are linked."
More to follow.