Several people were killed in a multi-car crash which caused explosions and a fireball on the M5 motorway in the southwest of England, police and media said.

About 27 vehicles including cars and lorries were involved in the crash on the motorway near Taunton Friday evening, injuring 35 people, some of them seriously.

Television pictures showed a line of cars and lorries engulfed in flames following the massive crash at around 2030 GMT Friday on the M5 motorway near Taunton, southwest England.

Around 50 firefighters battled to free people who were trapped in the wreckage of their vehicles on the northbound carriageway, and police said a long stretch of the major route was closed and would not reopen for 24 hours.

An unknown number of people died in the crash in fog and wet conditions. Witnesses saw a huge fireball and heard loud explosions.

'Some have tragically lost their lives,' Assistant Chief Constable Anthony Bangham said in a statement.

Blazing lorries fell over onto their side and people desperately tried to prise open the doors of cars to help trapped motorists escape in chaotic scenes after the crash, which happened in foggy and wet conditions, said media reports.

Eyewitnesses said they heard explosions as the vehicles went up in flames and saw debris and casualties strewn across the road.

'All emergency services are at the scene and are working tirelessly to attend to those who are injured or who are trapped in vehicles.'

British media reported that several people had been killed. Local resident Bev Davis described seeing a wall of flames at the crash site from her home close to the motorway.

'All we could hear was the sound of a horn and then the flames got so high so quickly and the noise was horrific,' she said.

'There must have been 200 metres worth of fire - plumes of smoke were going up and everything was red.' Motorist Paul O'Connor described the scene as 'horrific.'

'It was quite horrific and I have never seen anything like that -- I could see people lying on the side of the road,' he told Sky News television.

The motorway, the main gateway to England's southwest, is likely to remain closed in both directions for some time, police said.-Reuters