Los Angeles ? Rescue crews responding to a wreck on a Los Angeles freeway found a driver fatally shot in the head early Sunday, while another driver was shot and wounded in a separate attack about 30 miles away, authorities said.

The shootings were the latest in a string of attacks on Southern California freeways that have alarmed motorists and authorities.

Investigators did not know what led to the fatal shooting on the 101 Freeway in the San Fernando Valley on Sunday. The wreck snarled traffic for several hours near Van Nuys.

“There’s absolutely no witnesses at this time, no information,” Los Angeles police Officer Norma Eisenman said.

The car crashed near a freeway onramp, so it was possible the victim was shot before entering the highway, Eisenman said.

The second shooting was in Long Beach, where the victim was able to drive himself off the freeway and phone for help on Saturday night, Officer Jackie Bezart said.

The man told officers another motorist shot at him as the result of road rage along the 710 Freeway, Bezart said. The man was hospitalized with nonlife-threatening injuries.

Investigators do not think the cases were related to three other shootings, two that were fatal, in the past several weeks on Southern California freeways.