Rescuers believe it could take at least another two weeks to free miners trapped underground in eastern China, dashing hopes of an imminent retrieval for a group that has already spent 12 days entombed by an explosion.

Chinese rescuers drilled several fresh holes Tuesday to reach at least 12 gold miners trapped underground for nine days, as dwindling food supplies and rising waters threatened their survival.

At least 12 gold miners trapped hundreds of metres underground in China for more than a week have sent up a note warning some are injured, water surrounds them and they urgently need medicine.