A suspected gas leak caused a blast at a restaurant in China's northern province of Hebei that ripped facades from buildings, damaged cars and scattered debris to kill two people and injure 26, state media and authorities said on Wednesday.

The blast happened at about 8 a.m. in the county of Sanhe, state broadcaster CCTV News said, roughly 80 km (50 miles) from the centre of Beijing, the capital, where key annual parliament sessions had just concluded.

Videos on social media platform Weibo showed a large orange fireball over the site, followed by billows of grey smoke, and scenes of the destroyed frontage of buildings, mangled cars, with glass shards in the streets, and some objects still ablaze.

A suspected gas leak triggered the accident in a shop selling fried chicken in the town of Yanjiao, city emergency officials said in a statement, drawing rescuers, firefighters, health and other officials to the scene.

"I was at home when I heard a loud blast, I initially thought it might be a gunshot," said Zhao Li, a middle-aged woman who lives about a kilometre from the blast site.

"The loud explosion was accompanied by a crash of glass and clouds of smoke," said Zhao, adding that police sealed off the street to the site.

The fire had been brought under control, fire officials said in an earlier statement, adding that 36 vehicles and 154 people had been dispatched to the site and were carrying out rescue work.

China's latest deadly gas explosion at an eatery comes after the government issued detailed guidelines last year on the use of gas appliances and cookers to avert safety risks.

Social media posters on Weibo said the explosion occurred near a cultural centre in the town. Construction of a metro line was taking place nearby, Chinese weekly the Economic Observer posted on its social media account.

City emergency authorities sent an investigation team, according to social media posts.

Regional supplier Taida Gas suspended service in several surrounding areas, as a precaution to prevent secondary injuries, it said in a statement.

"Our company ... will resume supply after ensuring safety," it added in the statement, although it said it did not service the area where the shop is located.