WARSAW, Poland -- Rescuers have recovered eight bodies from the debris of a house destroyed by a gas explosion in southern Poland but are continuing to search in sub-freezing temperatures for any other possible victims, officials said Thursday.

Silesia provincial Gov. Jaroslaw Wieczorek said four of the dead in this "terrible tragedy" were children, as some 100 rescuers combed by hand through the debris.

The explosion Wednesday evening in the southern mountain resort of Szczyrk led to a fire that was put out before the search could begin.

"The rescue is being carried out in very difficult conditions, in hostile weather and in smoke from the debris," Wieczorek said. "Most of the work is being done by hand in order not to destabilize anything or hurt anyone."

Witnesses said the blast could be heard hundreds of meters (yards) away, as it shattered window panes in neighbouring houses.

Local residents said on broadcaster TVN24 they knew the people who died and expressed shock at the explosion.

Prime Minister Mateusz Morawiecki extended condolences to the relatives of the victims.

Firefighters said earlier that nine members of two families lived in the three-story house. One person was not at home at the time of the explosion.

A gas leak was the suspected cause of the explosion. Prosecutors and police were on site and investigating.

Footage on TVN24 showed firefighters and rescuers working through a huge heap of bricks that remained of the house. Hours later, the site was flat, after most of the debris had been removed.

A spokesman for Poland's gas company said gas services for a large part of the town were cut off after the blast for security reasons.