SAN DIEGO COUNTY, Calif. — The San Diego Police Department and Sheriff's Department responded to an anonymous phone call threat made to Del Norte High School on Thursday. Out of an abundance of caution, the high school as well as other schools in the area were placed on a brief lockdown.
The menacing statements were delivered in a "robotic-" sounding, computer-generated-style voice, according to the San Diego Police Department.
The threat prompted lockdowns at the high school just west of 4S Ranch Parkway, as well as at nearby Del Sur, Design39Campus and Stone Ranch elementary schools; Oak Valley Middle School; and Maranatha Christian Schools, a preschool-through-12th-grade campus off Camino del Sur.
The San Diego Police Department confirmed that all school lockdowns were lifted shortly after 2 p.m.
SDPD said in a tweet that students are reuniting with their parents and their investigation continues into the threat.
Junior Julia Herndon was reunited with her mom, Lisa Herndon. They shared an emotional hug.
"I'm so relieved," Julia Herndon said tearfully. "We were told to go into lockdown. We were sitting in the walkways and we could hear helicopters and everything."
"It was really hard. There was no cell service because everyone was texting their parents," she added.
She said hugging her mom was the best feeling in the world.
WATCH: Lockdown lifted at 4S Ranch area schools | Perspective from a mother and daughter
Police officers and sheriff's deputies took up positions at the campuses and searched them along with surrounding areas by ground and aboard patrol helicopters.
As of shortly before 1:30 p.m., there were no sightings of any armed or otherwise suspicious people at any of the schools or in adjacent neighborhoods, SDPD Lt. Adam Sharki told news crews.
"All the kids are safe," he said. "All of this is out of an abundance of caution. ... There are no reports of anybody with a weapon, nobody walking around on campus who's not supposed to be there."
Sharki acknowledged that tensions were particularly high in light of the fact that the threat came just two days after 19 students and two teachers died in a shooting rampage at Robb Elementary School in Uvalde, Texas.
"It's heartbreaking, [I'm] sitting at home listening to all of the things that happened a couple days ago in Texas, and I get a text from my daughter 'We’re going into lockdown.' You don’t know why, what’s going on, it’s just frustrating, it’s terrifying," said Herndon.
"Kids should not have to live like this," she added. "School is supposed to be a safe place. When it’s turning into a place they have to fear going to every day, we need to fix this. Something is wrong."
Poway Unified had sent out an email to staff and families during the lockdown stating "In an abundance of caution, the police have placed us on a brief lockdown while they investigate an anonymous phone call threat."
The email continued, "We want to assure you there is no evidence of actual physical threat present on our campus."
Police and sheriff's personnel will continue to investigate the threats to try to determine who is responsible, and there will be extra personnel at the six campuses as a precaution on Friday, according to the SDPD.
WATCH: Chopper 8 flying over Del Norte High School campus as students were released early from school after the lockdown was lifted on Thursday: