Japan has ordered emergency inspections of highway tunnels across the country after concrete slabs from the ceiling of a tunnel west of Tokyo fell onto moving vehicles Sunday, killing at least nine people.

On Monday, the government ordered the immediate inspections of the 49 other highway tunnels of similar design in Japan.

Safety officials are looking into the possibility that anchor bolts holding metal supports for concrete panels had failed. The tunnel, built in 1977, was last inspected in September.

Early Monday, rescue officials were forced to suspend their work on the collapsed tunnel until more supports could be added to the remaining panels.

Television reports shortly after the collapse showed black smoke billowing from the 4.7 kilometer Sasago tunnel in Yamanashi prefecture, about 80 kilometers west of Tokyo.