A serious crash has closed the M40 northbound between J4 near High Wycombe and J5 near Stokenchurch as an air ambulance landed at the scene and providing "critical care".

The southbound lanes of the road were also closed to accommodate the aircraft and traffic could be seen backing up in the area.

An update from National Highways UK said: "The M40 northbound in Buckinghamshire between J4 near High Wycombe and J5 near Stokenchurch is closed due to a serious collision.

"Traffic on the southbound carriageway has been stopped to allow the Air Ambulance to land safely at the scene."

The authority urged drivers to " re-route or even delay" journeys through the area as traffic began to pile up. Thames Valley Police's Roads Policing unit has warned the traffic disruption is likely to continue for some time.

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