An explosion and fire near a chemical factory left at least 22 people dead and 22 injured on Wednesday (Nov 28) in a northern China region that will host the 2022 Winter Olympics, authorities said.

View of Zhangjiakou, in northern Hebei province, north China. (Photo: AFP/Frederic J BROWN)

The incident near Hebei Shenghua Chemical in Zhangjiakou, a city some 200 kilometres (124 miles) northwest of Beijing, also burned 50 large and small trucks, the local propaganda department said on its Weibo social media account.

The injured were taken to hospital for treatment following the blast, which occurred at 12.41am local time, according to the statement.

The charred and smoking remains of trucks and cars were scattered on a road as firefighters worked at the scene, according to photos posted on Twitter by state broadcaster CGTN.

The statement did not say whether the factory was affected by the blast or whether it took place on a road.

"On-site search and rescue work and investigation of the cause of the accident are still under way," the department said.

Zhangjiakou will host the Olympic alpine skiing events at the 2022 Winter Games, which Beijing is organising.

It was not immediately clear if the explosion was near the site./.

Map locating a an explosion near a chemical plant that killed at least 22 in Zhangjiakou, China on Wednesday (Nov 28).

VNF/AFP