Four people in Shanxi province are trapped in an illegal coalmine after a gas accident, with rescue efforts underway, China News Service reported on Thursday.

The accident occurred at about 2:28 pm on Wednesday in a private mine operated illegally from a residential complex in Yangquan city, the report said.

Rescuers are attempting to drain water from the coalmine, the report said, but hopes for the survival of the four are slim.

On Feb 19, a similar accident also occurred in the city, leaving seven people dead, the report added.