Two lanes of the M6 motorway reopened yesterday afternoon more than 15 hours after a fatal crash involving a chemical container lorry.

Police were still investigating the cause of the head-on collision between a 23-ton BOC tanker carrying liquefied carbon dioxide and a second HGV, as well as two saloon cars.

Staffordshire Ambulance Service was called to the scene between junctions 15 and 16 of the motorway shortly before 9pm on Monday night and reported the tanker alight and throwing flames 50ft into the air.

A man in his 50s from the West Midlands died and at least four people were taken to hospital in Stoke-on-Trent.

A second driver was seriously injured and remained in a critical but stable condition at the North Staffordshire Hospital last night.

An 2,625ft exclusion zone marked the crash site and up to 105 people evacuated to nearby Keele motorway services.

The Highways Agency said repairs to road surfaces and safety barriers were due to be carried out last night.

A spokeswoman said the overnight work would reduce the southbound carriageway to one lane and the northbound route to two lanes for the duration.

The details of the crash and the people involved are unclear and the incident is being looked at by the Central Motorway Police Group and Staffordshire Police collision investigation department.

Staffordshire Ambulance Service said the accident happened when a vehicle on the northbound carriageway crossed the central reservation of the motorway.

A spokesman said the tanker exploded following the crash and that a service doctor who arrived at the scene shortly after the collision reported seeing the fire.

He said: " The doctor described the flames as being 50ft into the air and when he arrived, one of the lorry drivers had been dragged out by two motorists who had stopped."

Staffordshire Fire Service sent appliances from across the county to deal with the severe tanker blaze.