The fire started at a four-storey building belonging to the Yongju coal company in Luliang city at around 6:50 am local time (2250 GMT on Wednesday), state media said, citing local authorities.
Twenty-six people were confirmed dead, state news agency Xinhua reported.
Earlier, broadcaster CCTV said that 63 people had been evacuated from the site, 51 of whom were hospitalised. The reports did not say if any of those taken to hospital had died.
CCTV reported that the fire had been “brought under control” and that its cause was still under investigation.
Video footage posted on social media site Weibo showed bright flames and thick black smoke billowing from the building, while dozens of people stood in the parking lot watching.
The building shown in the video matched images of the coal company’s headquarters posted on its website.
Emergency response personnel could be seen in the footage racing to put on protective gear outside a fire truck parked at the building’s entrance.
‘Profound Lesson’
Chinese leader Xi Jinping, currently in the United States for a summit of Asia-Pacific leaders, said there was an “extremely profound lesson” to be learned from the fire.
Local governments must “conduct in-depth investigations of hidden risks in key industries, improve emergency plans and prevention measures”, he said, according to CCTV.
Xi called for “all efforts” to treat the injured as well as investigate who was responsible for the fire.
Industrial accidents are common in China due to lax safety standards and poor enforcement.
In July, 11 people died after the roof of a school gym collapsed in the country’s northeast.
The month before, an explosion at a barbecue restaurant in northwestern China left 31 dead and prompted official pledges of a nationwide campaign to promote workplace safety.
In April, a hospital fire in Beijing killed 29 people and forced desperate survivors to jump out of windows to escape.
One of the worst such accidents took place in 2015 in Tianjin, where a gigantic explosion at a chemical warehouse killed at least 165 people.
AFP