SEYMOUR, Ind. – Sniper attacks targeted two pickup trucks early Sunday on a busy highway, killing one person and wounding a second, and police asked other motorists who had been through the area to check their vehicles for bullet holes.

Hours later, two more vehicles were struck by bullets on another four-lane highway about 100 miles away. There was no immediate indication if the cases were connected, police said.

One shot struck a southbound pickup on Interstate 65 shortly after midnight, killing one of its two passengers, police said. At about the same time, a bullet grazed the head of a passenger in another southbound pickup on the same highway.

“The Indiana State Police will treat these incidents as being connected until proven otherwise,” Sgt. Jerry Goodin said. “We’re literally scouring hundreds of miles of crime scene.”

One pickup had a bullet hole near the top of the windshield on the passenger side. The second had a bullet hole in the middle of the windshield and a rear window was blown out.

About two hours later, bullets struck a tractor-trailer rig on I-69 near Muncie, northeast of Indianapolis, police said. Later, a parked SUV was struck at a service station in the same area.

Police closed a 14-mile stretch of I-65 for eight hours after the Seymour shootings.

Police identified the man who was killed as Jerry L. Ross, 40, of New Albany, Ind.