Oceanside High School was on lockdown Monday morning, according to school officials.
The high school at 1 Pirate Cove Way went on lockdown for 30 minutes around 11 a.m. The lockdown only lasted for 30 minutes.
Police said there were reports of shots fired nearby at the 400-block of Grant Street. Officials later determined the incident involved an altercation between two groups, and it is unclear if a gun was involved.
A man on the sidewalk allegedly picked up an object and threw it at a car with three people inside, according to Oceanside public information officer Steve Lombard. The object then shattered the car window.
Officials said the men inside the car believed it was a gunshot, so they allegedly sped off and crashed their car, nearly hitting a pedestrian. The men then fled on foot.
Lombard said it is unclear if there were any shots fired, or if witnesses mistook the rock hitting the car for a gunshot.
Police were concerned the men inside the car might go toward the school, which is why it was placed on lockdown. Officials said the car was stolen and they are investigating the incident.