CCTV shows youths throwing stones on to vehicles on M1
CCTV has been released by police of youths throwing stones and heavy debris on to passing vehicles from a bridge over the M1 in Bedfordshire.
A warning of the dangers to drivers and their passengers has been issued after reports of eight stone throwing incidents in the past six weeks.
Police are keen to catch those responsible.
They hope releasing the CCTV footage will encourage witnesses to come forward.
Sarah Wilkinson, from Bedfordshire Police, said: "It's possible these young people do not realise how dangerous their behaviour is.
"They may see stone throwing as just a prank.
"But a 44-tonne heavy lorry travelling at 50mph makes it extremely dangerous for the driver and others on the road if control of the vehicle is lost."