Someone threw a Molotov cocktail at a building that is part of St. Rose Church at 398 10th St. around 10 p.m., fire inspector Mark Pedroia said.
A priest who was asleep in the rectory heard a crash and discovered that a bottle filled with gas had been ignited and thrown against a wooden door at the west entrance of a building at the church complex, Pedroia said.
The priest was able to put out the fire quickly, Pedroia said.
Another Molotov cocktail was thrown at the Church of the Incarnation at 550 Mendocino Ave., across the street from St. Rose Church, Pedroia said. Only the fuel in the bottle burned in that case, he said.
In the third case, the Carlile-Macy building at 15 Third St., which houses an engineering, planning and architectural business, was targeted, Pedroia said. A bottle smashed against the brick wall of that building, leaving a smoke stain, he said.
Police are also investigating the incidents, Pedroia said.
