Florida officials are investigating a fire at a mosque attended by the gunman of the Orlando nightclub massacre, according to reports Monday. Initial evidence indicated that the fire was intentional and the sheriff’s office is investigating the incident as arson.

Emergency personnel responded to a call in the early hours of Monday, shortly after midnight, at the Islamic Center of Fort Pierce, Florida, according to the St. Lucie County Sheriff’s Office. Surveillance video showed a person walked up to the east side of the building before the fire broke out, Major David Thompson, of the Sheriff’s Office, said.

“Right now I don’t want to speculate on a motive,” Maj. Thompson said. “We all know the implications of the date and the time of year, this is the 9/11 anniversary. Is that related? I would not want to speculate but it is in the back of our minds.”

Thompson added: “This is a horrible tragedy, not only for the Islamic Center, but also for our community.”

Orlando shooter Omar Mateen, who killed 49 people at the Pulse nightclub, attended the same mosque. Coincidentally, Monday was also the Muslim holiday of Eid al-Adha.