RIVERSIDE, Calif. (AP) — The windows of dozens of vehicles have been shattered by BBs or pellets on Southern California freeways since April, authorities said.

The shootings have occurred primarily on a 45-mile (72.4-kilometer) stretch of the State Route 91 freeway between Cerritos and Riverside, authorities said.

No injuries have been reported so far in the string of shootings, which are under investigation by the California Highway Patrol.

The CHP said 4 additional attacks on late Tuesday night and early Wednesday brought the number to nearly 60 in recent weeks in Los Angeles, Orange and Riverside counties.

No injuries have been reported so far. 

A local trucking company said its drivers are now avoiding State Route 91 because of the shootings.

“I’m uncomfortable for the fact that our employees are subjected to something this terrible,” owner Patrick Maslach told local media.

The CHP is hoping that freeway cameras will help track down the attacker or attackers and are urging people to immediately report attacks or seeing suspicious cars, such as those with an open window or making evasive movements.