The shootings occurred at at least seven different locations in Rancho Tehama, including Rancho Tehama Elementary School, a small public school of 100 students.

Tehama County Assistant Sheriff Phil Johnston told local NBC affiliate KCRA-TV that "a number" of students had been medically evacuated from the scene, and that the school had been cleared.

"I know that we have medevaced a number of students," Johnston said. "I know that the school's been cleared. I know that we have children that were attending school in a safe location at this time."

In a later interview with The Associated Press, Johnston said the shooter was "randomly picking targets" and that the number of victims could rise. In addition to the school, Johnston confirmed that a woman and a child riding in a pickup truck were also attacked and both were wounded by the shooter.

Police said officers recovered a semi-automatic rifle and two handguns at the scene.

Johnston said that about 100 law enforcement personnel were spread out at "multiple scenes" in and around the school.

"We are spread thin, we have a lot of resources right now and you can see that we're still requesting ambulances and we're still doing our work," he said.

"We have had an active shooter incident at Rancho Tehama Elementary this morning," reads a statement from the Corning Union Elementary School District obtained by the LA Times. "There are confirmed injuries. We are cooperating with law enforcement during this investigation but do not have specific details at this time."