Fire and rescue services are on the scene after a lorry trailer caught ablaze just before 8.30pm on the northbound carriageway.
Police said there had been "things exploding" in the back of the trailer. Thankfully nobody has been injured but authorities say the road surface will need "urgent repairs".
Police and highways agencies are warning drivers to avoid the area if at all possible.
A diversion is in place, taking cars off the motorway at junction 32 at Broughton, and from the M55 up the A6 to junction 33 and southbound motorists are being rerouted at junction 33. However, some motorists are reporting they are stuck on the road and Highways England confirmed there had been a "block" put in place.
The southbound traffic was 'released' after a delay of more than an hour just before 9.45pm.
The North West Motorway police posted on social media: "Looks like this will be ongoing for sometime, avoid the area if possible."
Highways England said: "The HGV fire is very strong and traffic needs to be kept away from the scene."
Lancashire Fire tweeted: "We're currently attending a HGV fire on the M6 northbound between junctions 32 & 33. Both northbound and southbound carriages are closed as a result."
More to follow