At least 18 people were killed and 16 injured when a fire broke out at a martial arts school in central China in the early hours of Friday, according to the local government.

Official state news agency Xinhua reported that all victims were boarding pupils, while local media said they were aged between seven and 16.

The fire had been extinguished and authorities were investigating the cause of the blaze, a statement from the Zhecheng county government in Henan province, said.

Four local officials including the county party secretary were fired over the incident, reported the Henan Daily, a local state-backed newspaper, on Saturday.

Two more suspects were arrested in addition to the school's manager Chen Lin, the Henan Daily said.

There were 34 boarding students on the premises when the fire broke out, according to government staff quoted by Beijing Toutiao News.

Those hurt -- four of whom had severe injuries -- were rushed to a local hospital, where an unnamed doctor told local media they were "doing everything they could" to save them.

The cause of the fire was still unclear.

An official confirmed to AFP that the school was the Zhenxing Martial Arts Centre.

Local media reports described it as a "comprehensive martial arts training institution" that aimed to "strengthen the body through morality and martial arts".

An online listing for the school advertised hour-long classes each day for a range of martial arts disciplines and said the school "recruits boarding students year-round", but offered no further details.

Provincial party chief Lou Yangsheng told local media that the blaze was a "profound lesson".

The location of the martial arts school where at least 18 people were killed in a fire on Friday
The location of the martial arts school where at least 18 people were killed in a fire on Friday AFP / STAFF

The school had not gone through the fire safety auditing process required for martial arts training institutions, as the building had originally been a privately built house intended for other purposes, Xinhua reported Friday.

Henan is the birthplace of traditional Chinese martial arts and is home to many kung fu academies.

Among the largest is the famous Shaolin Martial Arts School, which has hundreds of teachers and tens of thousands of students, according to its website.

Social media users started to call for better fire safety standards online as a hashtag for the fire quickly garnered over 1.5 million views.

Fatal fires are common in China, with safety regulations often flouted and patchy enforcement.

More than two dozen people were killed in two blazes in Beijing's migrant neighbourhoods in 2017.

The first, which killed 19 people in November that year, prompted authorities to begin tearing down unsafe buildings in the capital, driving hundreds of thousands of residents out in the middle of winter.

A huge blaze that swept a 28-storey Shanghai residential block in 2010 killed 58 people.

Friday's blaze comes at a sensitive time for China's ruling Communist Party as it ramps up security preparations before its 100th anniversary celebrations on July 1.

Following a spate of deadly mine accidents in the past few weeks, local authorities this month suspended operations at coal mines in Henan, Jiangxi and Hubei provinces in the run-up to the anniversary.

In one week in June alone, more than 30 workers were killed in two separate gas explosions at mines in Henan and Hubei.