BREAKING- Arsonists Torch Mosque Which Pulse Nightclub Shooter Attended, Set On Fire Yesterday, On 9/11 Anniversary

A fire that broke out early Monday at the Fort Pierce mosque where Orlando massacre shooter Omar Mateen prayed and worshipped is considered arson, according to investigators.

"Evidence has revealed that this fire was set intentionally," St. Lucie County Sheriff's Major David Thompson told reporters. A 911 call about 12:30 a.m. alerted authorities that flames were coming out of Islamic Center of Fort Pierce, 1104 W. Midway Road.

There were no injuries reported and the extent of the damage has not yet been determined. According to Thompson, investigators were able to find surveillance video that shows someone approaching the east side of the Islamic Center.

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

He said the sheriff's office is asking the FBI and the Federal Bureau of Alcohol Tobacco and Firearms to join the investigation currently underway by local authorities and the State Fire Marshal's Office.

Additionally, technicians are working to enhance the surveillance video so it can be released to the public in order to turn up leads in the case.

Mateen, who lived in Fort Pierce, killed 49 people at Orlando's Pulse nightclub in June and was known to worship at the mosque. Mateen was killed in a shootout with police.

Leaders at the Islamic Center have said that since the nightclub shooting the facility has received threats and that security had been stepped up.

Thompson was asked about any coincidence between the blaze and the 15th anniversary of the 9/11 attacks.

"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," he said.