(CNN) -- At least nine people were killed Thursday when a tour bus collided with a truck in Glenn County, California, said California Highway Patrol Officer Timothy Howath.
CNN affiliate KRCR reported the passengers on the bus were students going to visit colleges. The bus collided with a FedEx semi-truck near Orland, the affiliate said.
"Our thoughts and prayers are with everyone involved in the tragic accident on I-5 in California. We are cooperating fully with authorities as they investigate," said FedEx spokeswoman Bonnie Kourvelas.
Images from the scene on Interstate 5 showed emergency workers around the vehicles' charred remains. Long lines of traffic snaked away from the accident.
Orland is about 100 miles north of Sacramento.
Karen White, spokeswoman with Shasta Regional Medical Center, said her hospital has received two patients.
"I don't know if any more are coming," she said.
In a statement, Humboldt State University in Northern California said it was working to find out more about the crash.
"Humboldt State University is getting word of an accident involving a charter bus that was bringing a group of prospective students to the university's April 12 Spring Preview Day," the statement read.
CNN's Dave Alsup and Carma Hassan contributed to this report.