A church elder opened a door that leads to the church's parish hall area about 5:15 p.m. and smelled smoke, Broward Sheriff's Office spokeswoman Liz Calzadilla said. The elder, Carl Barclay, immediately called 911.
Pompano Beach Fire-Rescue firefighters arrived and found a smoldering fire inside a storage room in the church, officials said. Firefighters promptly put out the fire.
Investigators think someone intentionally started a fire in a small box containing office supplies and a separate blaze in a nearby shopping cart holding doorknobs and other equipment, Calzadilla said. The items were inside the storage room, and the flames burned themselves out by the time authorities arrived.
No arrests were made.
"There's somebody who's either crazy or nutty out there," Barclay said. "Somebody who needs a little God in them."
Detectives are not sure whether Monday's fire is connected to blazes Wednesday that burned that church, at 3401 NE Third Ave., and an adjacent parish, Saint Mary Coptic Orthodox Church.
While the Seventh-day Adventist Church sustained minor damage last week, its neighbor's office was destroyed, and there was heavy smoke damage. A fire official said combustibles such as paper, wood and gasoline were probably used to start the blazes, which caused about $500,000 in damage.
Barclay said the part of the Seventh-day Adventist Church damaged in last week's fire is still under construction and may be vulnerable to more attacks. The Rev. Charles Possenriede said his church and Coptic officials are considering hiring a night security guard.
Sheriff's Office officials said deputies were called to both churches four times in the past two months. Windows were broken at the Coptic church in early March. Those incidents are being reviewed in connection with the fire investigation.
Mike Jachles of NBC 6 contributed to this report.