(CNN) — The gunman appeared to select his targets randomly: a mother driving with her children, a squat schoolhouse in rural Northern California, where students and teachers were starting their day.
At least five people are dead, including the attacker, after shootings Tuesday morning in at least seven locations in remote Tehama County, about 125 northwest of Sacramento, Assistant Sheriff Phil Johnston said.
Police fatally shot the lone gunman after a killing spree that appears to have begun with a domestic dispute and spread rapidly to Rancho Tehama Elementary School before ending in a roadside gunfight with police, Johnston said.
The victims included a mother driving her children to school when the unidentified attacker opened fire on them “without provocation or warning,” the assistant sheriff said.
The mother was being treated for life-threatening injuries; her child was not seriously wounded, according to Johnston.
Hours into an investigation that involves the FBI, the ATF and California Highway Patrol, the motive for the shootings remains unclear.
“We have no known motive,” Johnston told reporters. “We know of no real connection to any of the victims. Most of the victims in this case appear to be random selections.”
“This is a sad day for us here in Tehama County,” a visibly shaken Johnston told reporters.
“Anne and I are saddened to hear about today’s violence in Tehama County, which shockingly involved schoolchildren,” Gov. Jerry Brown said in a statement. “We offer our condolences to the families who lost loved ones and unite with all Californians in grief.”
Johnston said the gunman had “prior contacts with law enforcement,” but did not elaborate. He said there was a report of a domestic violence incident involving the man on Monday.
When the gunman arrived at the school, he fired multiple rounds into the building. He stole a truck and commandeered another vehicle from a motorist at gunpoint, Johnston said. There were reports that the shooter carried out random drive-by shootings on residences.
Some students were transported to hospitals by helicopter, and others were moved to a safe location in a school bus, the assistant sheriff’s said. The children were later reunited with their parents.
At least one student was shot at the elementary school, and another child was shot in a truck along with an adult female, Johnston said.
Three children and an adult are being treated at Enloe Medical Center in Chico, officials said. Their conditions were not available.
In all, 10 people were being treated at local hospitals.
Police were still trying to get an accurate count of the injured, Johnston said.
A semi-automatic rifle and two handguns believed to be used by the gunman, who engaged police in a shootout, have been recovered, according to Johnston.
The school district was cooperating with local law enforcement, according to its statement. No other details were available.