Saint Nicholas day falls on Dec. 6 and children in Poland and many other countries receive chocolates or other small presents ahead of the main Christmas celebration later in the month.

"The visit of the police officers caused a great stir among the little patients," police said in a statement. "The children were obviously surprised, but also very pleased."

Having succeeded in entering the building through the windows, officers dealt with the challenge of distributing the gifts around the wards by using a bomb disposal robot.

"The biggest thanks from the kids were the smiles on their faces," the police said.