Japanese police say at least five people have died after being trapped inside their burning vehicles when a highway tunnel collapsed west of Tokyo.
At least seven people were listed as missing after the collapse, which was triggered by a mudslide, saw large slabs of concrete crush at least two cars on Sunday morning.
It also sparked a fire which was later put out.
"A number of charred bodies were confirmed inside" a vehicle, a spokesman for Yamanashi Prefectural Police said on Sunday.
The Fire and Disaster Management Agency confirmed there were five bodies, adding another vehicle had also been burned.
"Other vehicles are believed to have been buried," it said in a statement.
The search-and-rescue operation, which had been suspended because of the risk of another collapse, was back on by late Sunday afternoon.
Fire and smoke from the cars initially proved a hindrance to firefighters who struggled to reach those believed trapped in the collapsed 50-60 metres of the Sasago tunnel.
The accident occurred on Tokyo-bound lanes, at around 8:00am local time, an official at the expressway traffic police said.
Public broadcaster NHK aired footage from inside the tunnel which showed a white ambulance and several firefighters wearing protective gear, working in an section shrouded in smoke. A number of cars with their lights flashing were also seen.
A 28-year-old woman was taken to hospital by ambulance after she emerged from the 4.3-kilometre tunnel by herself, the traffic police official said.
She told the rescuers she had been riding in a rented van with five other people, fire department official Kazuya Tezuka said.
"I have no idea about what happened to the five others," she said.
"I don't know how many vehicles were ahead and behind ours."
One witness, a reporter from Japan's national broadcaster NHK, happened to be driving through the tunnel when he said it started to disintegrate, concrete blocks were falling from the ceiling. He said he managed to escape but that the collapse trapped several cars adding as he escaped the tunnel he saw black smoke pouring from it.
Police confirmed an unknown number of vehicles were ablaze inside the tunnel and that there are injuries. A rescue is underway but as you can imagine it's a very difficult task with emergency services confronting thick smoke, blazing vehicles and a very precarious situation with fears of another collapse.
North Asia correspondent Mark Willacy
The tunnel, which passes through hills not far from Mount Fuji, is one of the longest in Japan and sits on a major highway connecting Tokyo with the centre and west of the country.
NHK said two other women were rescued from inside the tunnel and that the extent of their injuries was unknown.
Aerial footage on NHK showed several red trucks from the local fire department waiting outside the Tokyo side of the tunnel.
A man in his 30s, who was just 50 metres ahead of the caved-in spot when the accident happened, 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 a 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.
"The traffic was not so heavy."
A stream of people was seen coming out of the other exit after abandoning their vehicles in the tunnel, the broadcaster said.
Japan has an extensive and well-maintained network of thousands of highways throughout its mountainous terrain, usually several hundred metres long. Millions of cars use the network every day.