WARSAW, Poland (AP) - Firefighters in southern Poland say that seven people have been injured and two are missing after an explosion demolished half of an old Evangelical parish house in Katowice.

Firefighters say the explosion Friday morning was most probably caused by gas that was used for heating and cooking in the three-story brick house that belongs to the parish of the Savior.

The deputy head of the region's firefighters, senior Brigadier Miroslaw Synowiec, said a sniffer dog is helping in the search. The missing women lived in one of the apartments, firefighters said.

Witnesses told Polish media that small children were among those injured. They were all taken to a hospital.

An investigation has been launched into the cause of the explosion.