An explosion rocked a building whose occupants had complained Monday of an odor of natural gas. One firefighter was blown off a ladder and two others were briefly buried in rubble.

Seven firefighters were hurt in all, but none of the injuries were believed to be life-threatening, officials said.

The blast happened at a former gas station in north Minneapolis that was being used to disassemble computers for scrap metal. The occupants arrived early in the afternoon, smelled natural gas and called 911.

Fire Chief Bonnie Bleskachek said firefighters shut off the gas and left the building open so it could ventilate. When they went back in, it exploded.

One firefighter was quickly rescued after he stuck his arm above the rubble. Another was uncertain whether anyone would find him underneath the debris, and was thinking about how to dig himself out when he heard rescuers calling out to him, she said.

One firefighter was treated at a hospital and released. The others were admitted in satisfactory or fair condition. Firefighters suffered burns to their faces and hands, and one had a broken leg.

No names were released.

The building's roof and doors were blown off. The blast also shattered windows in other buildings in the neighborhood.