Two cars had their windows shot out while driving on the freeway at around 7:42 a.m. on Monday, the California Highway Patrol (CHP) told NBC Los Angeles.

Two more cars were then shot at by either BB or pellet guns just a few minutes later, with one incident taking place at 7:47 a.m. and the final at 7:49 a.m.

The four incidents took place during the space of just seven minutes, with the final two being reported to have occurred around half a mile from the original pair.

One unidentified victim who had his window smashed by the shooter told CBS Los Angeles that they were “just driving down the freeway, on my way to work, and all of a sudden I heard a real loud pop, and then I heard glass falling.”

The second victim, identified as Luther Castor, said that he remembered the previous reports of the shootings, so pulled over and called the police, while having to wait “30 minutes for them to show up.”

Since March 4, there have been at least 50 shootings suspected to have involved BB or pellet guns on freeways in Los Angeles, Orange and Riverside counties, with a majority of them taking place on the 91 Freeway.

No arrests have yet been made, while no serious injuries have been reported by the victims of the shootings, despite windows being smashed in the incidents.

Ramon Duran, a CHP Inland spokesperson, told CBS Los Angeles that investigators in the department believe that the cars are being shot at by a suspect in a moving vehicle.

“It’s extremely hard to catch somebody like that but we have investigators that are on it, from Riverside County, Orange County, L.A. County,” Duran said.

A man was involved in a car-to-car shooting on the 91 Freeway on Saturday, with a handgun recovered from the vehicle. However, the police do not believe that the shooting is related to the spate of incidents involving BB or pellet guns.

Aiden Leos, a six-year-old boy, was fatally shot during an apparent road-rage shooting on the freeway on Friday. His family have announced a $50,000 reward for any information that could lead to the arrest of a suspect.

Newsweek has contacted the CHP for comment.