A large plume of smoke could be seen over the accident near Livingston, Scotland, at 8.45am – but the fire has now been put out.
There are long tailbacks in the area.
The Scottish Ambulance Service had earlier said two people had been taken to hospital.
A police spokesman said: "Two cars, a can and an articulated lorry were all involved in the incident which resulted in three vehicles catching fire.
"The M8 is currently closed in both directions while emergency services are in attendance at the scene and it is due to remain closed of several hours.
"Full diversions are in place and congestion on the M8 is
now starting to ease."
Daily Star
Posted by Adebayo A J