Local firefighters spokeswoman Patrycja Pokrzywa said the detached, three-floor house in the popular mountain resort of Szczyrk was destroyed in the explosion shortly after 6 p.m. The regional firefighters' chief, Jacek Kleszczewski, said some 100 firefighters were working in sub-freezing temperature and snow to put out the last flames and allow for full rescue action.
Pokrzywa said children were believed to be among those trapped under the house, which was home to two families. She said rescuers with dogs were searching for survivors and victims. She said she received her information about the number of residents from a person who lived in the house but was outside at the time of the explosion.
Footage on TVN24 showed firefighters and rescuers trying to access a huge heap of bricks that the house had been turned into. A spokesman for Poland's gas company, Artur Michniewicz, said a leak from a damaged local gas pipeline most probably was responsible for the explosion.
He said that after the blast, authorities cut off gas for a large part of the town for security reasons. Szczyrk Mayor Antoni Byrdy said the search could last until as long as Thursday morning.