Following reports of floating flame-powered paper lanterns flying high above Somerville on New Year’s Eve, Fire Chief Kevin Kelleher last week banned all use of the celebratory orbs. Usually constructed of thin paper folded and glued into the shape of a globe and fueled by a single candle, the hollow parchment acts like a miniature hot-air balloon. The department said the airborne lanterns were first reported on a community website for Davis Square. “These devices are inherently uncontrollable and unsafe,” Deputy Fire Chief Patrick J. Sullivan III said in a prepared statement. “They can and do get blown onto rooftops before their fuel supply is exhausted, and they can easily start fires that are hard to detect until they become serious conflagrations. . . . “We want the public to know that the sky lanterns are completely banned.” There is a maximum fine of $1,000 for each device, according to state law. Sullivan urged residents to call 911 if they spot a lantern. “In a city like ours, sky lanterns can lead to a very unhappy new year,’’ he said. - Matt Byrne