Authorities have determined that a fire early Sunday at a Maplewood church was a case of arson.

Maplewood police and fire crews went to St. Jerome Catholic Church at about 12:40 a.m. on a report of a burglary and fire alarms sounding.

First responders arrived to find heavy smoke coming from the building in the 300 block of Roselawn Avenue E. They also found there had been "forced entry" into the building, said Maplewood police Lt. Joe Steiner.

Crews put out the small fire and secured the building, Steiner said.

A Bureau of Alcohol, Tobacco, Firearms and Explosives-certified fire investigator also responded to the scene, said ATF spokesperson Ashlee Sherrill.

"This incident appears to be an isolated incident resulting in minor property damage," Steiner said. "It remains an active arson investigation."

The FBI also is helping with the investigation.