A man arrives for prayers June 14, 2016, at the Islamic Center of Fort Pierce in Florida, where Pulse nightclub shooter Omar Mateen had worshipped.

Investigators have ruled as arson a fire that started early Monday at the Florida mosque where Orlando, Fla., shooter Omar Mateen worshipped, the Sun Sentinel reports.

"Evidence has revealed that this fire was set intentionally," St. Lucie County Sheriff's Maj. David Thompson told reporters.


Authorities responded to a 911 call about the fire at the Islamic Center of Fort Pierce at around 12:30 a.m. There were no injuries reported, and the extent of the damage done to the mosque was not clear.

Thompson told reporters that investigators found surveillance footage showing someone approaching the Islamic Center from the east side, before fleeing the area.


"Immediately after the individual approached, a flash occurred and the individual fled the area," he said.

The sheriff's office is asking the FBI and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives to join in the investigation currently being conducted by local authorities and the state Fire Marshal's Office.


Technicians are also working to enhance the surveillance footage so that it can be released to the public, authorities say.

Mateen, a Fort Pierce resident, killed 49 people at Pulse nightclub in June before being killed in a shootout with police. Mateen was known to worship at the mosque, and officials at the mosque have said that since the shooting, they have received threats, prompting security to be tightened.


According to the Sentinel, when asked about the fire and any possible correlation with the 15th anniversary of the 9/11 attacks Sunday, Thompson said, "We all know the implications of the date and the time of year that this is, the 9/11 anniversary. Is that related? I would not want to speculate, but certainly that is in the back of our minds."

The news site notes that Monday also marks the start of Eid al-Adha, the Islamic festival of sacrifice.


"This is a terrible tragedy, not only for the Islamic Center but for our community," Thompson added.

Read more at the Sun Sentinel.