Ruda Slaska, Poland ? Rescuers recovered the bodies of 15 more workers killed in a Polish mine explosion early today, bringing the death toll to 21 and leaving little hope that the remaining two missing men would be found, a mining company spokesman said.

The men were killed by Tuesday’s explosion more than a half-mile below the surface at the Halemba mine in southern Poland.

“Rescue workers recovered 15 more bodies,” said Zbigniew Madej, spokesman for the state-run Coal Co.

Attempts to reach the buried miners were halted repeatedly after high concentrations of gas raised fears of a second blast.

“Any spark could cause another explosion and more victims,” rescue worker Boguslaw Ozog said earlier.

Previously, teams had recovered six bodies from the scene of the blast, said Zbigniew Madej, spokesman for the mine operator.

Another two bodies had been found, but remained underground. Those two bodies were amonth the 15 recovered early today.

President Lech Kaczynski surveyed the site Wednesday and met with family members, pledging a full investigation. He canceled planned trips to Georgia and Romania this week.

“I should be here … even though these were very important visits,” he said.

Labor Minister Anna Kalata promised swift financial assistance for the families.

The miners, aged between 21 and 59, were trying to retrieve valuable equipment that was abandoned months ago in a section of the Halemba mine that was closed because of dangerously high gas concentrations.

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.