The Florida mosque where Orlando nightclub shooter Omar Mateen worshipped was targeted in an arson attack early Monday, authorities said.

Fire crews responded to a 911 call at 12:31 am reporting that flames were coming out of the Fort Pierce Islamic Center, Major David Thompson of the St. Lucie County Sheriff’s Office said.

Security video showed an individual approaching the building from the east, he said.

“Immediately after the individual approached, a flash occurred and the individual fled the area,” Thompson said.

“Evidence has revealed that this fire was set intentionally,” he said. “The sheriff’s office is currently investigating this as an arson.”

No injuries were reported and the extent of the damage was not immediately clear. 

Photographs posted on the sheriff department’s Facebook page showed fire engines parked in front of the building, a former church, with the facade appearing undamaged.

Authorities were working on enhancing the security video to help identify the perpetrator.

Forty-nine people were killed and another 53 injured on June 12 when Mateen, a 29-year-old U.S. citizen of Afghan origin, opened fire on the Pulse gay nightclub in Orlando. Mateen was killed by police.