SAN DIEGO – Del Norte High School and several other schools in the 4S Ranch area were temporarily placed on lockdown Thursday afternoon while authorities investigated an anonymous phone threat, police said.

San Diego police and the San Diego County Sheriff’s Department received a phone call “saying that somebody was going to shoot up Del Norte High School and a nearby elementary school,” Lt. Adam Sharki told reporters at the scene. The call was made using a Google phone number and a robotic voice was used, he said.

A lockdown was put into place at Del Norte High School as well as Stone Ranch, Monterey Ridge and Del Sur elementary schools as well as the Design39Campus, officials from Poway Unified School District said in emailed letters to families. Also on lockdown were Oak Valley Middle School and the private Maranatha Christian Schools, police said.

“We want to assure you there is no evidence of an actual physical threat on any campus,” Poway Unified School District officials said in a tweet.

“All the kids are safe, all this is out of an abundance of caution,” Sharki told media.

By 2:10 p.m., lockdowns had been lifted at all impacted schools and students were reuniting with their parents, police said on Twitter.

“There will be extra police presence tomorrow,” police said in the tweet.