Safety probe after fiery Japan tunnel collapse kills 9

TOKYO (AFP) - Japan ordered inspections of ageing highway tunnels on Monday after a fiery collapse that killed nine people, as suspicion over the cause of the accident centred on decaying ceiling supports.

The government pledged a thorough review and said "significant investment" would likely be required in the motorway network, parts of which including the accident site were built during the economic boom of the 1960s and 1970s.

"As a major factor, we suspect ageing," an official from highway operator Nexco said, referring to the tragedy at the Sasago tunnel which passes through hills near Mount Fuji 80 kilometres west of Tokyo.

Engineers on Monday began inspections at three other tunnels in the region with the same design, as well as the Sasago carriageway. There are around 20 such tunnels nationwide, reports said.