Hopes are fading of saving 15 Polish miners trapped after a gas explosion killed at least eight of their colleagues, officials have warned.
The blast was probably caused by methane gas, officials said
Rescuers worked through the night and day to try to clear 500m (1,640ft) of rubble to reach the men trapped some 1,000m (3,300ft) underground.
But they later suspended their efforts because of fears of another explosion.
The blast happened at the Halemba coal mine in Ruda Slaska, southern Poland, on Tuesday afternoon.
"The situation is getting worse down there and there are no rescue teams there," Polish President Lech Kaczynski said after visiting the site.
"Although one can never lose hope and has to fight to the very end, the situation is very bad."
Grzegorz Pawlaszek, head of the state-owned company, said the mine shaft had been closed in March because of high gas levels, but the miners were retrieving equipment worth $23m (17.9m euros; £12.1m) that had been left behind.
Anxious relatives have been waiting at the scene for news.
'It is hell'
Officials said the blast, at about 1630 local time (1530 GMT) on Tuesday, was probably caused by methane gas.
Rescue work was slowed by fears of a second explosion of suspected methane gas, a lack of oxygen and temperatures reaching 40C.
"The conditions down there are extreme. It is hell. It is impossible to breathe in the area of the explosion," said Zbigniew Madej, a spokesman for the state-owned coal company.
Rescuers have been trying to pump air into the shaft - it is not known if the breathing apparatus for the trapped miners will hold out.
Rescue efforts were suspended later on Tuesday.
Six bodies have been recovered. Another two have been located but could not be reached.
The identities of the dead could not be determined quickly as their ID tags had been blown away in the blast.
Ruda Slaska lies about 300km (190 miles) south-west of the capital Warsaw.
The prime minister flew to the site of the blast and has declared a period of national mourning for the dead miners.
Relatives say they are scared but have not lost hope
Priests have been counselling distressed relatives. Eight candles burned on a wall at the main gate.
"There are a couple of hundred people standing outside the entrance to the mine holding candles and flowers," Marek Piotrowski, who visited the site, told the BBC.
"It's a real tragedy for this community. But everyone is pulling together and hoping the 15 still trapped will survive."
The mine is in Silesia, the heartland of the Polish coal industry.
Safety conditions in Polish mines have improved since communist times, our correspondent says.
But unions have often complained of poor investment in the industry. More than 80 miners have died in the country since 2003. An explosion at the Halemba pit in 1990 killed 19 miners.
Are you in the area near the mine? Send us your comments using the form below.
The BBC may edit your comments and cannot guarantee that all emails will be published.