Police want to hear from anyone who witnessed last night's horror 14-car pile-up on the M40 near High Wycombe. 

Eleven injured people had to be rushed to hospital following the smash, which happened on the southbound carriageway between junction 4 for Handy Cross and junction 3 for Loudwater at around 5.45pm. 

The air ambulance was called, along with seven ambulance crews, two paramedic officers, a tactical advisor, two Hazardous Area Response Teams (HART), two High Wycombe fire crews, one from Beaconsfield, one from Gerrards Cross, one from Maidenhead and two officers as well as Thames Valley Police. 

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More than 20 casualties had to be assessed by medics, while 11 were taken to Wexham Park Hospital with serious or minor injuries. 

South Central Ambulance Service said a "large number of our ambulance family" attended to help at the scene - including two off-duty members of staff from a neighbouring ambulance trust and a hospital. 

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They added: "A huge thank you to everyone who attended."

A Thames Valley Police spokesman said officers are appealing for anyone who saw what happened or has dash-cam footage to come forward and help with their investigation. 

Call 101 quoting reference number 43200342787. 

Drivers were stuck in gridlocked traffic for more than two hours while the emergency services dealt with the crash.