Four people were injured Thursday morning in an accident near Aberdeen involving a school bus that did not have students on board, police and school officials said.
The incident occurred at 7:13 a.m. on Route 40 near the intersection with Route 7, when a vehicle crashed into the back of the bus, Harford County Sheriff's Office spokeswoman Cristie Kahler said.
Two adults and two children in the vehicle were injured, Kahler said, but added she did not know the extent of their injuries.
The bus driver and another adult on the bus were not injured, she said.
The accident caused "severe traffic back-up in the area," the Harford County Fire & EMS Association reported on its media Facebook page.
The bus is owned by Harford County Public Schools and was at the start of its run for the John Archer School near Bel Air, said Jillian Lader, manager of communications for Harford County Public Schools.
"The bus was starting its run, but had not picked up any students at the time of the accident and so there were no injuries on the bus," Lader explained in an email.