Police say it was rocks, not bullets, that shattered the glass on a public bus Saturday night in Baton Rouge.

Young people spotted throwing stones at a Capital Area Transit System bus traveling in the 4400 block of Fairfields Avenue about 7 p.m. caused at least one window to “slightly shatter,” said Baton Rouge Police Cpl. Don Coppola on Monday.

But a person claiming to be a passenger on the bus at the time of the incident told The Rouge Collection, a local website, that “shots rang out and came through the window,” which appeared to be pierced all the way through, according to a photo posted on the site.

Coppola said based on the initial report of the event, gunfire does not appear to have been involved. He said he could not say whether rocks were recovered in or around the bus on Monday.

There are no suspects or arrests in the case, but juveniles were seen running from the scene, he said.

No one was injured in the incident.

CATS spokeswoman Amie McNaylor said the probe is being handled by the Police Department and referred questions about the investigation to the police. CATS does not employ investigators to do a follow-up review of this type of event, she said. McNaylor was not able to confirm whether the glass on the bus had been fully shattered and what type of projectile was thrown at the bus, but she added that the bus driver followed protocol in the event.