Diversions have been put in place on the M4 after a serious crash closed the motorway in both directions. 

Wiltshire Police tweeted a 'serious road traffic collision' between junction 17 and junction 18 has caused the M4 to close and will remain closed for several hours. 

Emergency services are currently on the scene. 

UPDATE: TWO DEAD AFTER DOUBLE M4 CRASH

Highways England has released what diversions are best and said two serious crashes has caused the closure.

From Swindon, Highways said: "Westbound road users are advised to follow the solid diamond diversion route on road signs.

"Exit the M4 at J17 and take the first exit from the roundabout onto the A350 and travel approximately 2.5 miles towards Cepen Park North.

"At the roundabout take the second exit and follow the A350 through two further roundabouts until reaching the roundabout for the A420.

"Take the third exit from the roundabout onto the A420, follow the A420 for approximately 10 miles through Giddeahall, The Shoe and Marshfield.

"At the junction with the A46 take the A46 northbound for approximately 3.5 miles, then take the first exit at the roundabout to re-join the M4 at J18 westbound."