The blast -- which shattered windows in other shops and twisted iron gates over storefronts -- gutted the Xiyangyang, or Happy Sheep Hot Pot Restaurant, in Jinzhong City, Shanxi province, China's official Xinhua news agency reported.
The restaurant was filled with customers when the explosion occurred at about 8 p.m. Friday.
Yuan Heping, who was eating with his wife and some friends, suffered minor burns. He said there was no hint of any problems.
"Suddenly, there was a big bang and the hot wave ensued," he told Xinhua. "The whole room was engulfed in black smoke and I had to use my sweater to cover my mouth before I managed to jump from the second-floor window."
Local officials said six people died in the explosion and eight were pronounced dead after being transported to hospitals. Some of the injured suffered serious burns.