Yesterday the first group of rescuers and divers entered the flooded mine in the northern province of Shanxi but they returned within hours.
The situation underground is described as "very difficult" and there have been no further signs of life after tapping was heard the previous day.
The divers said black, murky water was complicating efforts to reach the site where rescuers hope 153 miners are still alive.
The next step in the rescue plan is under discussion but a further attempt is not expected until later today, officials said.
Television footage has shown rescuers tapping on pipes with a wrench, then cheering and jumping after hearing a response – the first sign of life since the mine flooded last Sunday.
They lowered pens and paper, along with glucose and milk, down metal pipes into the mine.
But nothing new had been heard since yesterday afternoon according to Wen Changjin, an official at the mine.
It is still not immediately clear what risks rescuers were taking by entering the Wangjialing mine.
However, a 3,000-strong rescue squad is working non-stop to pump out the water that poured in last Sunday when workers digging tunnels broke into an abandoned shaft.
Wen said the water level underground had dropped by about 15ft as of yesterday afternoon.
Experts said it could take days to reach the miners – and their survival depended on whether they had decent air to breathe and clean water to drink.
"They're doing probably the only thing they can do, which is to pump water as fast as they possibly can," said David Feickert, a coal mine safety adviser to the Chinese government.
The 153 workers were believed to be trapped on nine different platforms in the mine, which was flooded by enough water to fill the equivalent of 55 Olympic swimming pools.
Rescuers said four of the platforms were not totally submerged.
A preliminary investigation found that the mine's managers ignored water leaks from the abandoned mine before the accident, the state administration of work safety said.
China's coal mines are the world's deadliest.
Accidents killed 2,631 coal miners in China last year, down from 6,995 deaths in 2002, the most dangerous year on record. Last year more than 100 miners died in an underground explosion.