The mosque where Pulse nightclub shooter worshipped was set on fire on Muslim holy day Eid

Members of the Islamic community in Fort Pierce, Florida, woke up to find that their local mosque had been set on fire overnight in the early hours of the Muslim holiday Eid al-Adha, a four-day festival that started on Monday and signals the end of the pilgrimage to Mecca. 

Omar Mateen, the gunman who killed 49 clubgoers at Pulse nightclub in June, worshipped at the Islamic Center of Fort Pierce before his death in June. 

Authorities were clear that this fire was intentional and is being considered an act of arson. 

"Evidence has revealed that this fire was set intentionally," said St. Lucie County Sheriff's Major David Thompson, according to the Sun-Sentinel. 

Authorities responded to a 911 call at about 12:30 a.m. that said flames were coming out of the mosque. According to Thompson, surveillance video shows a person approaching the east side of the Islamic Center, a flash occurring and then the individual fleeing the area. 

Authorities report no injuries, and they have not yet reported the extent of the damage inside. 

Islamic Center leaders told the Sun-Sentinel that the facility has received several threats since the Pulse nightclub shooting. 

This weekend marked the 15th anniversary of the 9/11 attacks. Monday marks the three-month anniversary of the Pulse nightclub shooting.

"We all know the implications of the date and the time of year that this is, the 9/11 anniversary," Thompson said, according to the Los Angeles Times. "Is that related? I would not want to speculate but certainly that is in the back of our minds."

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

According to community advocates in Florida, the attack is nothing new for the Ft. Pierce Muslim community.  

"We are very weary because this is one more of a chain events that this specific community has been a victim of," Wilfredo Ruiz, communications director for the Council of American-Islamic Relations-Florida, said in a phone interview. "And the worst part of it is the incidents have come in a crescendo. It started with threatening calls, then moved to physical violence. And now, setting the mosque on fire, burning an hour after people left the mosque." 

He added, "The incidents are becoming more egregious, more violent, more criminal — and that's what worries the community."

Anti-mosque attacks have been on the rise in the last year. 2015 was the worst year on record for anti-mosque vandalism and it prompted President Obama to visit his first mosque as president.

The Fort Pierce arson is not the only anti-Muslim news to come out of the 9/11 anniversary weekend. On Saturday, Mic reported on an anti-Muslim attack in Brooklyn, New York, in which a woman tried to rip the hijabs off of two Muslim women and then push over one of the woman's baby carriages.