Two drivers were seriously injured and taken to the hospital after unknown individuals threw or dropped large rocks from a pedestrian overpass onto US-95/IR-11 in Las Vegas, authorities said.

According to police Nevada State Police, the incident occurred shortly before 9:00 p.m. local time on Sunday, just north of Railroad Pass Casino in Henderson.

Four vehicles sustained moderate to severe damage. Rocks impacted the windshields and bodies, causing crashes and serious injuries to two of the drivers.

Suspects on the run

When officers arrived on scene, the perpetrators had already fled. Police are asking for the public's help in locating them and are asking anyone with information or who witnessed the incident to call the Nevada State Police Investigations Division at 702-668-3261.

Authorities have not revealed details about possible motives for the attack, but warned that it was an extremely dangerous incident that could have been fatal.