At least seven people were feared missing after parts of a tunnel collapsed Sunday on a highway west of Tokyo, trapping vehicles as smoke from a fire inside initially prevented rescuers from approaching.

Video footage from cameras inside the tunnel, after the fire was extinguished, showed firefighters picking their way through cement roof panels that collapsed onto vehicles inside the Sasago Tunnel, about 50 miles (80 kilometers) outside the city. However, local media reported rescuers had suspended work out of fears of another collapse in the tunnel.

A woman who escaped from her rental car after it was trapped in the (2.5 mile) 4.3 kilometer-long tunnel told authorities that she was unsure about the condition of five other people who had been in the vehicle with her. Another two vehicles were known to be buried in the rubble, suggesting at least seven people were trapped inside, according to a statement by the Fire and Disaster Management Agency.

It said two people were confirmed injured, one of them moderately.  

The cause in the collapse of about 330 feet (100 meters) of the tunnel was under investigation. 

Police vehicles, fire trucks and ambulances were massed outside the tunnel's entrance. A man who said he saw the collapse and alerted authorities to the emergency told NHK television he managed to escape after he was ordered to flee. The roof and windows of another vehicle parked on the roadside outside the tunnel were crushed, and the injured occupants reportedly taken to a hospital. (AP)