Fire broke out early Friday morning in a music room at Monterey Trail High School in Elk Grove.
The school's fire alarm went off around 5:30 a.m., Elk Grove Unified School District spokeswoman Liz Graswich said. Cosumnes Fire Department firefighters responded and put out the fire, but not before the room sustained "moderate" smoke damage, she said.
"There may be some loss of equipment but we're still investigating that," Graswich said.
Students were moved to another classroom Friday, and officials hope to have them back in their usual band room by Monday. They should know by then whether any instruments will have to be replaced, Graswich said.
Graswich said the fire "does appear to be suspicious," and noted a Cosumnes Fire arson investigator is looking into the incident.