A 27-vehicle pile-up on a British motorway in foggy and wet conditions sparked explosions and an inferno, leaving several people dead and around 35 injured, police and eyewitnesses said Saturday. Television pictures showed a line of cars and lorries on fire following the massive crash at around 2030 GMT Friday on the M5 motorway near Taunton, southwest England. Blazing lorries flipped onto their side and people desperately tried to prise open the doors of cars to help trapped passengers escape in chaotic scenes after the crash. Eyewitnesses said they heard explosions as the vehicles went up in flames and saw debris and casualties strewn across the road. 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. Assistant Chief Constable Anthony Bangham, of Avon and Somerset Police, said "several people" lost their lives in the crash but did not give a precise figure. "The officers and the other emergency services faced a very, very difficult scene when they arrived," he told the BBC. "Many vehicles were on fire and the collision itself involved what we believe to be about 27 vehicles, both lorries and cars. "So they were faced with virtually all of them on fire. Many of them have burnt literally to the ground." Around 35 people were believed to have been injured, he said. 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 told the BBC. "There must have been 200 metres (660 feet) 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. "It was quite disturbing really." Jon Adair said on Twitter: "Worst traffic accident I've ever seen on the M5 nr Taunton. Burning vehicles & casualties/debris strewn across road." Jason Sharp, who witnessed the accident from a nearby rugby club, told the BBC that he heard a number of explosions. "Petrol tanks I believe were going up -- black smoke going up," he said. He said there was heavy fog and the roads were wet at the time of the crash. Paul Slaven, of Devon and Somerset Fire and Rescue Service, said the fierce fire was likely caused by the number and type of vehicles and he had no indication they were carrying any toxic or chemical material. "At least two of the vehicles on fire were articulated lorries and there would be a lot of fuel on them," he said.