Two people were killed in separate shootings on a western Oklahoma interstate early Thursday after a man drove through three counties firing randomly from his pickup truck targeting at least four vehicles, authorities said. The suspected shooter later surrendered and was being held in a county jail.

Custer County Sheriff Bruce Peoples said reports came in late Wednesday of a man firing at vehicles on Interstate 40 in Canadian County, which is adjacent to Oklahoma City. The man apparently continued driving west on the interstate, firing as he drove erratically and at a high rate of speed, the sheriff said.

The Oklahoma State Bureau of Investigation says 45-year-old Jeffrey Kent Powell of Arapaho was traveling with his wife when their vehicle was struck by gunfire. The agency says Powell was pronounced dead at the scene near Hydro, which is about 60 miles west of Oklahoma City.

Investigators say another person was shot and killed about 10 miles from there. The agency says 63-year-old Billie Jean West of Lone Wolf was hit by gunfire and pronounced dead at a hospital in Weatherford.

In both cases, the driver was able to pull over to the shoulder of the road after the shooting, Peoples said.

The suspect eventually surrendered without incident early Thursday in Custer County, Peoples said. Authorities have not yet interviewed him to determine a motive, but they don't suspect anyone was specifically targeted.

"He shot so many vehicles that it would have be totally impractical to assume he knew them," Peoples said, describing the case as a suspected road rage incident.

Investigators say the suspect is being held in the Custer County jail on a driving under the influence complaint, but more charges are likely. They say at least two other vehicles were struck by gunfire in the incident, but those drivers escaped injury.

The Associated Press contributed to this report.