WARSAW, Nov. 22 (Xinhua) -- At least eight coal miners were killed, 15 others missing, when a methane gas explosion took place in a coal mine in southern Poland on Tuesday evening, officials said on Wednesday.

    The explosion was the largest mine accident in Poland this year,increasing the number of miners killed in 2006 in the country to 28, according to reports.

    Rescue teams had recovered six bodies from the scene of the explosion 1,030 meters underground in the Halemba coal mine in the southern Polish city of Ruda Slaska, said Zbiegniew Madej, a spokesman for the Weglowa company, which operates the mine.

    Another two bodies had been located but could not be reached because of the high concentration of methane gas, he said.

    The fate of the other 15 was unknown. Locator devices carried by the missing miners emitted no signals, said Madej.

    As the ventilation facilities had been destroyed, the miners who remained buried underground were in a very dangerous situation,he said.

    A small reconnaissance team sent deep into the mine on Wednesday to locate the missing miners had to withdraw temporarily because of high gas levels.

    "The rescue managing staff decided that it cannot expose the health and the life of the rescuers to danger," he said.

    "This is probably the most difficult and dangerous rescue action in Poland in many years," Dominik Kolorz, a miners' trade union official, said on TVN24.

    However, the rescuers would never give up their efforts, said Madej.