Reported by official news agency Xinhua, the flood occurred around 7.20 am local time on Monday at the Gaomendong coal mine near Pingdingshan city.

Forty-two people were underground at the time, with only eight managing to escape.

Chinese officials said they were confident the trapped miners could be saved.

Rescue headquarters vice-chief Li Hanwei said the gas density was low and the amount of flooding was not huge when the accident happened.

According to reports, he said it was believed the miners were trapped about 800m from the pit’s entrance and 200-300m underground.

Over 800 rescuers were reportedly clearing silt from a blocked 30m section of the tunnel while others drilled towards the trapped miners.

The cause of the flood is not yet known.

Most of the miners are reportedly farmers from surrounding villages and families have gathered around the scene.

The flooding is reportedly the third accident in less than three weeks in Henan Province.

The Gaomendong mine is a legal colliery targeting annual production of 60,000 tons, according to the provincial government.

Another flooding accident on October 30 at the Mazhuang mine of Jiyuan City killed two people and 19 others remain missing.

The political fallout resulted in the dismissal of four government officials.