Media playback is unsupported on your device Media caption The BBC's Rupert Wingfield Hayes says emergency inspections of other sections of the tunnel - and of other tunnels in Japan - are taking place

The Japanese government has ordered emergency inspections of road tunnels across the country following a deadly roof collapse west of Tokyo.

Nine people were confirmed dead after concrete panels collapsed and started a fire in the Sasago tunnel, 80km (50 miles) from the capital on Sunday.

An inquiry into the Sasago collapse has also been launched.

Officials from the highway operator suggested that metal rods securing the concrete panels may have loosened.

Anchor bolts

Analysis The tunnel collapse raises all sorts of questions about Japan's ageing road infrastructure and inspection regime. Firstly there's the question of why the tunnel passed a five-yearly inspection just two months ago. Was the inspection thorough enough? If not, why not? Japanese media is reporting that it was mainly a visual inspection, i.e. men with flashlights looking to see if there were any visible cracks. Crucially, the steel struts that hold up the concrete ceiling of the tunnel did not undergo an "acoustic" inspection. This is the process by which inspectors use hammers to hit the concrete or steel supports to check their integrity by listening to the sound they make. The second question is how many other tunnels may be affected by the same problems. Among the 49 other road tunnels in Japan of a similar age and design is Japan's longest road tunnel, the 11km (six miles) long Kan-Etsu. If those tunnels need to be closed while they are inspected, it is going to cause major traffic problems. This very mountainous country is criss-crossed by long road tunnels, and you simply can't get around much of Japan without using them.

Japanese media report that the ministry of land, infrastructure, transport and tourism has ordered highway operators overseeing tunnels similar to Sasago to carry out emergency inspections.

A total of 49 other tunnels on roads managed by the government are being inspected, the ministry said.

Japan's highway network has more than 1,500 tunnels and officials estimate that about a quarter of these are more than 30 years old.

The BBC's Rupert Wingfield-Hayes in Tokyo says the new inspections will be more intrusive.

He says the focus of the investigation into the Sasago incident will consider why an inspection just two months ago did not spot anything wrong.

In the accident, 270 concrete slabs, each weighing 1.4 tonnes, came crashing down at about 08:00 local time on Sunday (23:00 GMT Saturday).

Japanese media say that the company that owns Sasago had relied on rudimentary visual inspections there, with no reinforcement or repairs since construction in 1977.

Officials are also quoted as saying that during the regular checks of the tunnel's ceiling, there had been no acoustic survey of the metal pieces on which the panels which collapsed rest.

Motohiro Takamisawa, from Central Nippon Expressway (Nexco), which operates Sasago, said metal rod failure could have been to blame.

Debris was all around, and it was virtually impossible to rescue anyone. Witness at scene of collapse Japan media on tunnel collapse

"At this moment we're presuming that the top anchor bolts have come loose," he said.

A possibility being explored was that the bolts holding the metal piece suspending these panels had become aged, Satoshi Noguchi, an official with the highway operator, told the Associated Press news agency.

Recovery work has now been suspended at Sasago while the roof is reinforced.

Badly burned

Chief Cabinet Secretary Osamu Fujimura told a news conference on Monday: "The prime minister ordered the transport ministry to put the utmost efforts to rescue victims, to quickly investigate the cause of the accident and to establish measures to prevent similar accidents and to provide a counselling service to victims."

Rescue crews finally began bringing the bodies of the nine dead out of the tunnel on Monday morning.

Some were reported to have been so badly burned they would take days to identify.

Three charred and smashed vehicles could also be seen being pulled from the tunnel's mouth, our correspondent says.

Image caption Recovery work is continuing at the Sasago tunnel, west of the Japanese capital Tokyo, following a roof collapse on Sunday that killed nine people. In pictures: Japan tunnel recovery work

Among the dead was a truck driver who had on Sunday called his company from his mobile phone saying he was trapped.

Five bodies were also recovered from a van. They were identified as three men and two women, all in their 20s and from Tokyo, Kyodo news agency reported. Another woman, 28, who had been in the vehicle survived.

Three bodies were found in another car.

Yamanashi prefectural police spokesman Yoshihiro Seto told the Associated Press news agency it could not be ruled out that more bodies or survivors could be found, but that the possibility was low.

The twin-bore Sasago tunnel on the Chuo Expressway in Yamanashi prefecture is one of the longest in Japan at 4.3km (2.7 miles).

Both sections will remain closed indefinitely.

In 1996, 20 people were killed when a tunnel in Hokkaido, northern Japan, collapsed and falling boulders crushed cars and a bus.