Poland says all 23 coal miners trapped after a gas explosion have died, making it the country's deadliest such accident in decades. The tragedy at the mine in Ruda Slaska, about 300 kilometers southwest of the capital Warsaw, occurred Tuesday, but rescue efforts were hampered by risks of further blasts. Stefan Bos is monitoring developments for VOA from Budapest.

Against all odds, anxious relatives had been hoping that at least some miners survived Tuesday's explosion at the Halemba coal mine in Ruda Slaska. "That woman has three children," another woman cried.

Some people, burning candles, prayed at a shrine of St. Barbara, the patron saint of miners, near the blast site. But their hopes faded away when rescue workers recovered the remains of the last missing men of a group of 23 miners, who had been trapped about one kilometer underground.

Officials said the miners, aged between 21 and 59, were attempting to retrieve equipment from an area that was closed in March because of dangerously high gas concentrations. On Wednesday search operations were suspended when rescue teams also noticed high concentrations of gas, which they feared could trigger another explosion.

Poland's Prime Minister Jaroslaw Kaczynski arrived at the mine and declared a period of national mourning. In comments aired on Polish radio, he promised an official inquiry into the accident.

"There will be a thorough investigation conducted to establish the direct reasons leading to the situation," he said. "Already during my short discussion, several hypotheses have been drawn. However, we have to bear in mind that it remains highly probable the developments had been triggered by natural forces."

The nearly 50-year-old Halemba mine, located in the heart of the Silesia industrial region, is one of the oldest in Poland and it has a record of serious accidents. Labor unions say safety standards have fallen in recent years because the mainly state-run mines have been strapped for investment since the collapse of Communism in 1989.

Tuesday's accident was the deadliest in decades and brought the number of deaths in Polish mine accidents this year to 46, up from 21 in 2005.

Polish mines employ more people than any other industry in the country, and last year thousands of miners marched in protests against planned job cuts.

The latest mining accident hit an already depressed region that witnessed another tragedy this year when just 10 kilometers away, a Polish exhibition hall collapsed. That accident killed 65 people and injured more than 160.