Four dead in petrol station blast

West Virginia police sealed off the scene of the blast

An explosion has levelled a petrol station in West Virginia, killing at least four people and seriously injuring nine others, reports say.

The cause of the blast is not yet clear but authorities suspect a propane tank exploded as a fire crew - responding to a reported gas leak - arrived on site.

A firefighter and a paramedic were among the injured, a state fire marshal's office spokesman said.

The explosion was felt at least a mile (1.6km) away at a local ski resort.

The explosion occurred at about 1045 (1545 GMT) at the Flat Top Little General Store, where little remained except a pile of debris.

"I thought we got struck by lightning. The whole building shook. The power went off," said Ben Monast, manager of a shop at the ski resort.