Motorists have been forced to leave their vehicles after a chemical tanker caught fire on the M6 in Warwickshire.
The motorway has been closed in both directions between junctions two and four, the Highways Agency said.
Drivers close to the tanker, which caught fire between junctions three and 3A, were evacuated from their cars and an 800m exclusion zone is in place.
Ambulance crews are treating 10 people with breathing difficulties. One is understood to be the tanker driver.
Warwickshire Police said the tanker had suffered a tyre blow out and then caught fire.
'Massive tailback'A force spokeswoman said: "Due to the motorway being closed there is a massive tailback of traffic and we are currently advising people to stay away from the area.
"Fire service are in attendance at the moment at the vehicle and it looks like it could be quite a long job.
"The fire is in a rural area, with few houses. Residents are being advised to stay indoors and close their windows."
Warwickshire cricketer Darren Maddy said he was stuck on the southbound carriageway for some time.
He said: "I can't see a great deal other than a big queue of cars.
"There's been a lot of fire engines and ambulances and police cars.
"The northbound section of the motorway is completely empty.
"We're aware it's something very serious. Other than that it's very frustrating."
Another eyewitness said people were leaving their cars on the carriageway and walking up the slip roads to Corley Services.
The Highways Agency advised northbound traffic to come off at junction two and use the A46 southbound, A45 and then A452 in order to rejoin the motorway at junction four.