Officials have declined to say what the device was, WXIA-TV, Atlanta, reported Wednesday.
Firefighters responding to the Tuesday afternoon fire said they found a severely burned male inside the apartment. He was hospitalized with what was reported as burns to more than 90 percent of his body.
Georgia Tech officials confirmed the injured man was a student at the university, but declined to identify him pending notification of relatives.
"Our primary concern is to provide appropriate assistance to the victim and for his family as well as his classmates," the university said in a statement.
The incident was under investigation by the FBI's Joint Terrorism Task Force, the Atlanta police department and Atlanta Fire-Rescue.
Atlanta police Officer John Chafee said "at this time, we are assisting in furthering the investigation to determine how the male received the injuries and how the fire started," the Atlanta Journal-Constitution reported.
WSB-TV reported police indicated a flammable liquid had been put in a bottle, causing it to explode.