Photo taken by cellphone on Aug 11, 2016 shows the explosion site at a power plant in Dangyang, central China's Hubei province. [Photo/Xinhua]

BEIJING - The death toll from a power plant explosion in central China's Hubei province has risen to 22, the State Administration of Work Safety said Saturday.

The blast occurred at Madian Gangue Power Generation Co. Ltd. in Dangyang City around 3:20 pm on Thursday. Preliminary probes showed it was caused by a broken high-pressure steam pipe when workers were testing thermo-power facilities.

The plant and neighboring companies have been closed and a work safety overhaul has been launched in the city.

The administration has sent a work group to oversee the operation and conduct an investigation.