One of the girls had gone to the escape room to celebrate her birthday, the official said.
Monika Kosiec, a spokeswoman for police in Koszalin, said the victims were thought to have been celebrating one of their birthdays.
A 26-year-old man employed at the facility which was installed in a rented dwelling was admitted to hospital with burns.
Horrific details have emerged about the deaths of five teens who were killed while locked inside a recreational "escape room" in Poland when a fire broke out.
Firefighters found the victims' bodies on Friday after they extinguished a fire at the escape room site next to the locked room.
Autopsies showed that the girls, who were friends from school, died of carbon monoxide inhalation. According to initial findings, the fire brigade, the fire broke out in an adjoining room.
Forensic and other police experts examine the site of a fire in an Escape Room, in Koszalin, northern Poland, on Saturday, Jan. 5, 2019.
In a follow-up tweet he demanded that the cause of the fire "must be fully explained". Asphyxiation is the probable cause of the deaths.
A fire engine at the scene of the tragic escape room fire.
There are around 150 Escape rooms across the United Kingdom with more than 50 in London alone and the craze for escape room adventures has increased year on year since 2013.
"We have provided psychological, psychiatric care to the families", Koszalin Mayor Piotr Jedlinksi told TVN. The game is in the last few years in many countries becoming more and more popular. They were the first known deaths in an escape room, a form of entertainment that has been growing in Poland over the past five years.
The Polish President Andrzej Duda called the horrific incident a "tragedy" as he tweeted out his condolences.