Los Angeles ? Four fires over 11 days at religious buildings were deliberately set, likely by a single arsonist, authorities said Wednesday.

The buildings were a Presbyterian church, a Bahai community center and two synagogues in the Encino area of the San Fernando Valley. No one has been injured.

A small incendiary device appeared to have been tossed through a window of the Valley Beth Shalom synagogue, Los Angeles Mayor James Hahn said at a news conference there.

“You know these senseless acts are more than just crimes,” Hahn said.

“People have come here because maybe they faced persecution in other countries for practicing their faith. So this is something we can’t tolerate here in Los Angeles.”