The accident took place in a coal mine of Yesanguan Mining Company in Badong County yesterday.
A similar accident that left one worker dead occurred six days ago at the same coal mine, according to the State Administration of Coal Mine Safety.
The flooding this time occurred when the six workers were working underground to clean the site from the previous accident, state-run Xinhua news agency reported.
In July, China's work safety watchdog vowed to close over 1,700 accident-prone small coal mines in a bid to enhance safety and reduce casualties.
Also Read
But he did not give a specific timetable for the shutdown.
In the first half of 2014, 51 coal mine accidents in these counties killed 122 people.
Small coal mines in China usually have outdated safety- control measures and are vulnerable to flooding or gas explosions.