The fire broke out around 9:00 pm (1300 GMT) Tuesday night at the nursing home in Longhua County, roughly 180 kilometres (112 miles) northeast of the Chinese capital Beijing, Xinhua said.

As of 3:00 am Wednesday, it added, twenty people were confirmed dead.

"Other elderly people in the nursing home have been transferred to nearby hospitals for further observation and treatment," the state news agency said.

The cause of the blaze is under investigation, it said.

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

In January, a fire 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.