The blaze was reported Saturday morning at a three-story building used by University of Southern Maine students, reported the National Broadcasting Company (NBC), adding that it was not immediately clear whether the victims were students of the university, Xinhua reported.
Seven people managed to escape without injuries, while one person who jumped out of a window had serious burns. The injured was reportedly flown to Boston for treatment and was in critical condition, according to NBC.
People inside the building had been celebrating Halloween the night before, the broadcaster said.
Neighbours told NBC affiliate WCSH that the residents of the building are mostly in their 20s. The number of victims and those unaccounted for remains fluid since not everyone who lives there may have been home at the time, local officials said.