Any hopes for survivors of a deadly mine explosion in southern Poland vanished Thursday after rescuers recovered the bodies of all 17 men who had been missing, bringing the final death toll to 23.

The men were killed by Tuesday's explosion more than a kilometer (3,280 feet) below the surface at the Halemba mine in southern Poland.

"This brings to an end this very sad day," said Zbigniew Madej, spokesman for the state-run Coal Co., at the scene. "Nobody has a sense of relief, but rather a great weight on their heart."

Six of the bodies were recovered shortly after the explosion and the remaining ones were located after rescue efforts resumed in the night, Madej said.

The search had to be put on hold for most of the day Wednesday when teams encountered high concentrations of gas that they feared could cause a second explosion.

It resumed shortly before midnight and the rescue teams found the bodies after digging through hundreds of meters of rubble for more than three hours, Madej said.

In addition to bringing down the rubble, the methane gas explosion would have produced temperatures of some 1,000 Celsius (1,800 Fahrenheit), Madej said.

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It may take some time to determine whether the miners were killed in the initial blast, by the cave-ins, or whether they died afterward, rescue officials said.

Ahead of the news that the remaining bodies had been found, anxious family members prayed at the shrine of St. Barbara, the patron saint of miners, near the mine.

Hundreds of red and white candles burned outside the entrance to the mine complex through the night.

President Lech Kaczynski, who surveyed the site on Wednesday and met with grieving family members, has pledged a full investigation. The government has also promised financial assistance for the bereaved and a review of safety at all Polish mines.

The miners, aged between 21 and 59, were attempting to retrieve equipment from a shaft that was closed in March because of dangerously high gas concentrations.

The Coal Co. said equipment worth 70 million zlotys (US$23 million; euro17 million) was left behind, and the team hit by the explosion had been sent in to retrieve it under the supervision of specialists.

Labor unions complain that a lack of investment and massive layoffs in recent years have resulted in falling safety standards at the nation's mines.

The nearly 50-year-old Halemba mine, located in the heart of the Silesia industrial region, is one of the oldest in Poland, and has a record of serious accidents.

In 1990, 19 miners were killed and 20 injured in a gas explosion at the mine. In 1991, five miners were killed in a cave-in.

Poland's worst mining accidents were in 1974 and 1979, when explosions killed 34 miners each at the Czechowice-Dziedzice in Silesia and the Dymitrow mine in Bytom.