A fire in a coal shaft caused by an electrical cable fault has killed 28 miners in northern China.

The accident happened at the Xiaonangou mine in Sangshuping township in northern Shaanxi province on Saturday evening, an official with the State Administration of Work Safety said on Sunday.

All the 28 miners working in the shaft were killed when the underground cable caught fire, he added.

An investigation was under way and local authorities ordered province-wide inspections at coal mines to avert further accidents, the Huasheng Daily, a local newspaper, said on its website.

Another eight miners also died in a mine fire in central Henan provice.

China's vast coal mining industry is notoriously accident-prone due to lax regulation, corruption and inefficiency as mines rush to meet soaring energy demand.

A total of 2,631 miners were killed in China last year, according to official figures, but independent labour groups say the actual figure could be much higher as many accidents are covered up to avoid costly mine shutdowns.

In another accident on Saturday, eight coal miners were killed in a blaze in a pit in neighbouring Henan province, the state-run Xinhua news agency said in a separate report.

On June 21, an explosion killed 47 coal miners at a huge state-owned mine also in Henan when a store of gunpowder kept underground detonated, state press reports said.