PITTSBURG, Calif. -- Investigators believe a fire at a Pittsburg church Saturday morning was set intentionally, but the official cause remains under investigation, a dispatcher said Sunday.

The blaze was reported just before 9 a.m. at the Church of the Living God in the 1100 block of Harbor Street, a Contra Costa County Fire Protection dispatcher said.

Firefighters rang a second alarm immediately after arriving at the church due to heavy smoke coming from the building but canceled the second alarm minutes later when they controlled the flames, according to the dispatcher.

No injuries were reported, she said.

The fire caused $75,000 damage to the structure and $50,000 damage to its contents.