A road tunnel has collapsed in Japan, trapping a number of vehicles, Japanese media reports say.
The incident happened at about 08:00 local time (23:00 GMT Saturday) in the Sasago tunnel, about 80km (50 miles) west of the capital Tokyo.
Public broadcaster NHK quoted its reporter as saying that black smoke was coming out of the tunnel and there appeared to be a fire inside.
Seven people were feared trapped in the tunnel, later reports said.
Pictures from closed circuit TV cameras inside the tunnel showed a section of the tunnel of up to 30m (100ft) that had caved in on the Tokyo-bound lanes on the Chuo Expressway in Yamanashi prefecture.
"We don't know exactly how many vehicles are on fire," a traffic police official told the AFP news agency.
The official added that a woman was taken to hospital after she had made her way out of the tunnel.
The woman said she was with five other people in a van, but added: "I have no idea about what happened to the five others. I don't know how many vehicles were ahead and behind ours."
A reporter for NHK described driving through the tunnel as it began to collapse, seeing other cars trapped and on fire. His car was badly damaged, he said.
Another survivor told the broadcaster that he saw "a concrete part of the ceiling fall off all of a sudden when I was driving inside. I saw a fire coming from a crushed car".
He added that he was "frightened" and walked for an hour to get out of the tunnel.
The Sasago tunnel is an estimated 4.3km-long (2.7 miles). The twin-bore tunnel is on one of the major highways out of Tokyo, the BBC's Rupert Wingfield Hayes in Japan reports.
The road has had to be closed because of the seriousness of the accident, our correspondent adds.
Firefighters are still trying to extinguish the blaze.