The young children were hurt in the accident at the Rovani nursery school in Sesto San Giovanni, on the outskirts of Milan.
A three-year-old girl suffered a non-serious head injury, while six of her classmates suffered light injuries. All of the hurt children were taken to hospital, Rai News reported.
Local mayor Monica Chittò ordered the school to be closed while the fire service carried out checks, although she said the building was thought to be structurally sound.
“There have not been any signs [of structural damage] in the school. “They [the fire service] told me that it was an unpredictable event, probably due to a thermal shock,” Chittò was quoted as saying, referring to a rapid change in temperatures which causes material to fracture.
Italy was subjected to freezing temperatures over the Christmas period, although the mercury has since risen and reached around 10C on Thursday.