Ashrad Shaikh, vice chairman of the Islamic Center of Northeast Florida, said the minor explosion and fire Monday night has shaken members of the mosque, the Jacksonville Times-Union reported. About 60 people were inside at the time, and the fire was put out with an extinguisher.
"I thought we were making so much progress -- that we had started getting beyond tolerance to friendship," Shaikh said Tuesday. "We have never, ever had anything that even came close to what we had last night."
Video from a security camera shows a man with a gas can outside the building, although it does not show him planting a bomb.
The bombing is being investigated by a task force including the FBI and other federal, state and local agencies. FBI spokesman Jeff Westcott said it is being treated as a hate crime.
Investigators are unsure if the bombing is related to an incident in April when a man entered the mosque during prayers and yelled, "Stop blaspheming," before members of the congregation chased him out.