The blaze erupted at lunchtime in Liaoyang City, about 580 kilometres (360 miles) northeast of the capital Beijing, according to state broadcaster CCTV.

"The incident has resulted in 22 deaths and three injuries," it added.

President Xi Jinping said that the blaze had caused "significant casualties" and that the lessons from it were "profoundly serious", CCTV said.

Xi called for "every effort to treat the injured, properly handle the aftermath for the deceased and provide support to their families, swiftly determine the cause of the fire, and pursue accountability in accordance with the law," the report added.

Footage shared online and verified by AFP showed the inferno engulfing the two-storey restaurant and smoke billowing skyward.

Other authenticated videos published on Douyin, China's version of TikTok, showed paramedics wheeling one victim on a stretcher into an ambulance and several firefighters battling the flames with hoses.

Another video from the social media platform shot from above the scene showed more than a dozen fire engines parked outside the restaurant.

- 'Very tragic' -

One woman working at a nearby restaurant said she hadn't been outside all day and only learnt of the incident when she read news articles about the fire.

"We weren't aware of it and continued on normally," she told AFP over the phone.

The woman, who did not want to be identified, said she had "no idea" what caused the fire but said she heard sirens and there were still police outside of her restaurant.

"It definitely was very tragic," she added.

Deadly fires are relatively common in China due to lax building codes and an often slipshod approach to workplace safety.

The country has seen a spate of such deadly incidents in recent months.

This month, 20 people died in a fire at a nursing home in northern China's Hebei province.

And in January, a blaze at a vegetable market in Zhangjiakou city, northwest of Beijing, killed eight people and injured 15.

A month before that, nine people died in a fire at a construction site in eastern China's Rongcheng city.