RICHMOND -- A one-alarm house fire that crews knocked down and controlled in about 10 minutes revealed a marijuana grow operation, a fire official said.

Fire crews were called to the 1800 block of Hellings Avenue around 4 a.m. Tuesday morning, and saw flames coming from the residence, Richmond Fire Battalion Chief Manly Moulton said. Nobody was inside when they arrived, and crews quickly put out the flames, he said.

No injuries were reported.

Fire investigators are still working to determine the cause of the blaze, Moulton said, and police also are investigating. No arrests had been made as of Tuesday afternoon.

Contact Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rderh.