The arson is the 23rd such incident since early November. Most have occurred in or near the Russian Hill area, police spokeswoman Sgt. Lyn Tomioka said.
This one, reported at 4:25 p.m. Sunday at the intersection of Kansas and 15th streets, was far from Russian Hill, and arson investigators have not said whether they believe the same arsonist is responsible.
"They're not speculating if it's the same person, or a copycat," Tomioka said.