Interior Minister Joachim Brudzinski said the girls were all 15 years old.

Monika Kosiec, a spokeswoman for police in Koszalin, said the victims were thought to have been celebrating one of their birthdays. She said a 25-year-old man had been sent to hospital with burns and could not immediately be questioned by investigators about the cause of the fire.

Spokesman for regional firefighters, Tomasz Kubiak, said the bodies were found in a room that was near the fire but was not hit by it.

The Polish state news agency PAP said it had learned unofficially that the girls died from carbon monoxide asphyxiation.

Footage on private station TVN24 showed ambulances and fire engines in front of a detached two-story house with a large escape room sign in front.

Brudzinski ordered fire safety checks to be held at all similar attractions across the country.

The premise is the subject of a new film, Escape Room, that opened in North American cinemas on Thursday.

President Andrzej Duda said on Twitter it was a “crushing tragedy” that five young girls died so early in their lives.

Koszalin Mayor Piotr Jedlinski announced that Sunday would be a day of mourning in the city.