The incident occurred at around 2:30 p.m. Tuesday, Nov. 15, at Nassau Community College in Uniondale, according to Nassau County Police.
Investigators said the man set fire to a poster on a wall in the gym, which was occupied at the time, causing damage.
A college spokesperson declined to elaborate on the extent of the damage or say how many people were inside the building at the time.
There were no reports of injuries stemming from the fire.
Nassau County Police released surveillance footage showing the suspect wearing a blue or gray hooded sweatshirt with a black graphic t-shirt and blue pants. He also has a goatee with a gray beard.
Anyone with information is asked to contact the Nassau County Police arson bomb squad at 516-573-8850 or contact Crime Stoppers at 1-800-244-TIPS. All tips remain anonymous.
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