Several people are believed to have been injured in a multi-car pile-up on a major road.
The A40 has been closed in both directions after multiple vehicles crashed into each other near Witney in Oxfordshire at around 8.25am, police said.
Images showed the mangled wreckage of several of the cars involved, with debris strewn across the road.
The incident is likely to cause major disruption for many people travelling across the country following the Christmas break, as the road connects London to Wales.
A Thames Valley Police spokesman said: "Thames Valley Police officers were called today at about 8.25am following reports of a collision involving multiple vehicles on the A40, Witney.
"Officers are at the scene along with the fire and rescue services. A number of people are believed to have been injured.
"Road closures are currently in place, and drivers are advised to avoid the area."