UPDATE: M40 southbound reopens after 'serious crash' involving two lorries

Two lorries are reported to have been involved in the crash between J5 (Stokenchurch) and J4 (Handy Cross) going southbound on the busy motorway, as thousands of motorists are expected to take to the roads for the school summer holidays.

Highways England tweeted at around 2.15pm to say an air ambulance had been called to the scene, and has now confirmed the motorway is open.

One lane was closed as emergency services worked to clear the scene and there were delays back to J7, but Highways England has tweeted to confirm all lanes are now open and delays have cleared.

It came after a lorry fire caused the M40 to be closed off at J4 due to heavy smoke.

According to traffic links, there was also "severe congestion" on the A40 eastbound between Stokenchurch and High Wycombe due to traffic being diverted from the M40.

All lanes now open and collision clrd on the #M40 s/b btwn J5-J4. Traffic flowing with no delays. Have a safe journey.

— Highways England (@HighwaysEAST) July 21, 2017

#M40 clsd s/b btwn J5-J4 due to a multi vehicle collision. #Airambulance in attendance. For diversion follow - https://t.co/tXZTV8QDen

— Highways England (@HighwaysEAST) July 21, 2017

#M40 now open again s/b btwn J5-J4 but lane 1 remains clsd for @tvprp to carry out collision investigations. Delays back to J7 currently.

— Highways England (@HighwaysEAST) July 21, 2017

A40 E/Bnd
Severe Congestion btwn Stokenchurch and H/Wycombe
Due to diverting traffic from M40 pic.twitter.com/c4ySfpSXgW

— Traffic Mick (@TrafficMick) July 21, 2017

M40, closed south at junction 5 due to serious collision. Expect delays, avoid if possible. #p1417 pic.twitter.com/F95CDM5BKY

— TVP Roads Policing (@tvprp) July 21, 2017

The #M40 is now BLOCKED southbound within J5 due to a multi-vehicle collision. Emergency services are on scene.

— Highways England (@HighwaysEAST) July 21, 2017