Two students were wounded and an adult gunman was sought off-campus following a shooting Tuesday in a Nevada high school parking lot, authorities said.

Police launched a search for a blue Mustang and a driver seen in a convenience store videotape after a teenage student in a green Pontiac Grand Am was wounded in the ankle and a female student was wounded in the abdomen as she walked through the parking lot before classes at Western High School. Police said it was unclear if the girl was struck by a bullet or a shrapnel fragment.

"It appears to be a road rage incident," police Officer Jose Montoya said of the shooting, reported just before 6:30 a.m. "It's not school-related or gang-related."

The two wounded students were taken to University Medical Center, where the teens were treated for wounds that authorities said did not appear life-threatening.

Montoya said the wounded boy was one of three teens in the Grand Am that nearly collided with the Mustang at a corner convenience store gas station a few blocks from the campus, about three miles west of downtown Las Vegas.

Detectives saw the man in a security video from the store, where words were exchanged between people in the vehicles before the Mustang followed the Grand Am to the school parking lot, Montoya said.

He said the man in the Mustang fired at least five shots at the Grand Am with the teens inside before driving away.

The two teenagers who were in the car but were not wounded provided police with good descriptions of the gunman, who Montoya said was in his late 20s or early 30s, with braided hair.

Students arriving for school found the parking lot blocked by police, but Clark County School District officials did not cancel classes. The campus has an enrollment of 2,423 students.

A Clark County school police officer and another motorist also were hurt in a collision Monday morning while the officer was responding to the shooting call, authorities said.

Police said officer Bryon Grimes, 39, was treated for moderate injuries. Frank Kocka, 46, the driver of the other vehicle, was treated for minor injuries but not hospitalized.

Police said Grimes had the lights and siren activated on his patrol cruiser when it collided in an intersection with Kocka's 2004 Saturn sport utility vehicle.