ROCHESTER, Minn.  — Safety officials have a new warning about the popular sky lanterns after one ignited a fire at a Rochester hotel.

The lanterns are made of paper and are carried aloft by hot air generated by a candle. Occasionally the lanterns remain lit after they fall from the sky, which is what happened this week at the America’s Best Value Inn in Rochester. A lantern ignited a small fire on the hotel roof, which was extinguished by firefighters.

Winona Fire Capt. Jason Theusch tells KTTC-TV  that even though the lanterns are being sold in some retail stores in Minnesota, they are, in fact, illegal.