Some 77 people, including many women and children, were staying in the three-story building in Kamien Pomorski, when it burned to the ground early Monday morning.

Witnesses said the fire brigade only had ladders long enough to reach the first floor windows, and that many of the survivors jumped from the building to escape the flames.

Pawel Fratczak, a spokesman for Poland's national firefighters, said the fire broke out around 1 am, and that most of the survivors had already fled the building before firefighters arrived.

Fratczak said 20 people were taken to hospital with broken bones and other injuries after escaping the blaze.

"The fire spread at an incredible speed," rescuer Daniel Kopalinski said at the scene. "Firefighters had to catch children thrown through windows by their parents," he added.

Firemen are still searching the ruins for more victims.

It was not immediately clear what caused the fire.

A government spokesman said Prime Minister Donald Tusk was on his way to the scene.