At least nine people have died after being trapped inside burning vehicles when a highway tunnel collapsed in Japan, crushing cars and triggering a blaze.
The bodies were found in three vehicles that were crushed by fallen concrete panels in the Sasago tunnel, about 80km west of the capital, Tokyo, the BBC reports.
A fire broke out after the tunnel caved in about 8am on Sunday, and there are fears the death toll may rise further.
Witnesses spoke of terrifying scenes as at least one vehicle burst into flames, sending out clouds of blinding, acrid smoke, AFP reports.
For several hours rescuers were forced to suspend their efforts to reach those believed trapped under the more-than one tonne concrete ceiling panels that crashed from the roof as engineers warned more debris could fall.
Emergency crews who rushed to the tunnel were hampered by thick smoke billowing from the entrance.
Dozens of people abandoned their vehicles on the Tokyo-bound section of carriageway, and ran for one of the emergency exits or for the mouth, where they huddled in bitter winter weather.
Emergency crews equipped with breathing apparatus battled around a third of the way into the tunnel, where they found 110 metres of concrete panels had come crashing down, crushing at least two vehicles.
Hours after the collapse, engineers warned the structure could be unstable, forcing rescuers to halt their work for several hours as a team of experts assessed the danger.
Survivors describe scene
One man who fled the tunnel told the Jiji Press news agency he had watched in horror as concrete crashed down onto a vehicle in front of him, leaving little more than a mound of dust and debris.
Voices cried out "Help" and "Anyone please help" from the pile before a young woman emerged with her clothes torn, he was reported as saying.
She could not stop trembling, he told the agency, as he asked her how many had been inside the vehicle.
"She said: 'All of my friends and my boyfriend ... Please help them,'" said the man, adding the flames were too strong.
Footage from security cameras in the late afternoon showed large concrete panels in a V shape, apparently having collapsed from the middle, with teams of men in protective gear scrambling over them.
A man in his 30s, who was just 50m ahead of the caved-in spot, recounted details of the terrifying experience.
"A concrete part of the ceiling fell off all of a sudden when I was driving inside. I saw fire coming from a crushed car. I was so frightened I got out of my car right away and walked one hour to get outside," he told NHK.
A woman who walked out of the tunnel told rescuers she had been riding in a rented van with five other people and did not know what had happened to them, ABC reports.
A reporter from Japan's national broadcaster NHK who was driving through the tunnel said that as it started to disintegrate, concrete blocks fell from the ceiling.
The tunnel, which passes through hills near Mount Fuji, is one of the longest in Japan. It sits on a major road connecting Tokyo with the centre and west of the country.
The Japanese authorities have begun emergency inspections of tunnels across the country after the collapse.
An inquiry into the collapse has also been launched.
Police are investigating potential negligence, but the private company that runs the highway, the Chuo Expressway, says the tunnel was given a clean bill of health in a major inspection two months ago.
However, company officials have suggested that metal rods securing the concrete panels may have loosened.
Japan has an extensive web of highways with thousands of tunnels, usually several hundred metres long. Millions of cars use the network every day.