Fourteen people have been injured, some seriously, in what was described as a “horrendous” car crash in Stevenage.
Two cars collided on Monkswood Way at about 21:45 BST on Thursday evening during what has been reported as a car cruise event.
The East of England Ambulance Service said 12 of the injured were taken to three hospitals in Stevenage, Watford, and Harlow.
Police asked witnesses with footage of the crash to send it to detectives.
According to some posts on social media the collision happened during a car meet event, and some of those injured were watching from the side of the road.
Footage posted on Twitter shows one car passing another before the two collide and one ploughs into spectators.
One witness said on Twitter: “I’ve just witnessed that horrendous crash in Stevenage, no more than 50ft away from me. I’m still trying to process it all.”
A Hertfordshire Police spokeswoman said: “There were a number of people in the area at the time and 14 people are presently being treated for injuries, some of which are serious.”
The air ambulance was also sent to the scene.
A group called Cruise-Herts had said it was holding a cruise event where people gather to look at modified cars.