Arvin High School students were released early Monday after police received a report — which they ultimately found to be unsubstantiated — that a man was outside the school armed with a handgun in the morning, police officials said.

The report launched a three-hour ordeal that drew law enforcement officials from across the county to Arvin High School. They determined by the afternoon that there were no shots fired, no injuries, and no gunman to be found.

The campus was placed on lockdown shortly after a woman called the Kern High School District Police Department at 10:36 a.m. to report a man with a gun, Kern County Sheriff’s Office Sgt. Stephen Wells said. After that, officers sweeped the campus for more than three hours searching for the suspect, according to KHSD Police Chief Ed Komin said.

“We’ve checked every inch of this school,” Komin told reporters at a 1:15 p.m. press conference. “We determined there was never anybody with a gun on campus.”

During the ordeal, which prompted a response from KCSO, KHSD Police Department, California Highway Patrol, Kern County Fire Department, Arvin Police Department and even the Federal Bureau of Investigations, rumors ran rampant. Local media reported early that a man was holding victims hostage, which KCSO Sgt. Wells described as “misinformation.”

He described the situation as “a whole bunch of nothing.”

But the hysteria, which prompted scores of concerned parents to show up to the school before noon, was largely driven by social media rumors, Komin said.

“We’re going to hear rumors because these are high school students. One student sends a student an embellished message, and another student sends another one that gets embellished message, and before you know it, we have a mass event on our hands, when in fact, we didn’t,” Komin said. “We never did.”

There will be a heightened police presence at Arvin High for the rest of the week, Komin said.