Police have renewed an appeal to find two teenage yobs who threw rocks at cars from a bridge on the A12.

The mindless youths almost killed a mother and daughter from Silver End when a fist-sized stone smashed their windscreen.

Annette Challis, 49, and her daughter Jade were travelling home from Colchester in their Proton Savvy when the stone hit the driver’s side windscreen.

Fortunately, Ms Challis managed to keep control of her vehicle.

A second car was also struck on the afternoon of April 10, but police were unable to find the youths.

Adam Pipe, casualty reduction manager for Essex Police, said: “It’s not common.

"There was a real concern around this a few years ago.

“We had a really nasty incident on the A12 between Chelmsford and Mountnessing.

“They are probably being opportunistic and the real worry is that during the school holidays sometimes they see it as a bit of fun.

“It’s incredibly dangerous.

"They probably fail to acknowledge the seriousness of their actions.  If they did, they probably wouldn’t do it.”

The boys are described as being aged about 13 or 14.

The first is described as having blond layered shoulder-length hair and wearing a grey sweatshirt with a white T-shirt underneath and blue jeans.

The second boy had dark hair and was wearing a red jumper.

Anybody with information should contact PC Trevor Sleet at Chelmsford Roads Policing Unit on 101.