Authorities placed Poly High School on lockdown shortly after 3 p.m. Wednesday after police received a call about a person with a gun at the school—though police later said there is no indication that an armed person entered the Central Long Beach campus.

The suspects left the area before police got there, police spokeswoman Arantxa Chavarria said. Officers conducted a safety sweep of the school, and no weapons had been recovered.

Police said the incident happened off 15th Street between Atlantic Avenue and Martin Luther King Avenue, though authorities said there were no reports of any shots fired.

Police sent an advisory notice to parents to pick up their children near the Smart & Final parking lot at Anaheim and Atlantic.

Chris Eftychiou, spokesman for Long Beach Unified School District, said most students were dismissed earlier in the day, but some remained on campus.

“The campus is on lockdown as a precaution due to a report of a potential incident that occurred off campus,” Eftychiou said in an email. “The remaining students on campus are safe.”

One football player, Evan Arredondo, said he and his teammates were getting ready for practice when they heard "3 big booms" and they started running for the locker rooms. Not everyone heard booms though. — Valerie Osier (@ValerieOsier) September 20, 2018

Students were waiting at Poly Burgers in the same the parking lot for their parents Wednesday afternoon.

Most students left at the campus participate in extracurricular activities.

When the lockdown was called, football players were getting ready for practice, the track team was just finishing practice and the robotics team was in the middle of its meeting, among other sports and activities.

“It didn’t seem real until everyone started running and that’s when I was like, ‘Oh this isn’t a drill,” said sophomore Alyssa Jones.

Sophomore football player Evan Arredondo said his teammates started running when they heard “three loud booms,” although police said there were no reports of gunshots.

“The coaches gathered everyone up in the locker rooms to make sure we were safe,” Arredondo said. “I feel safe now.”

While students were hanging out, some parents were still waiting for their kids to get released from the school.

“I’m just thinking of the safety of my daughter,” said a parent, John Q. “I was worried … but the only thing you can do is sit and wait.”

More to come.