(CNN)Authorities are responding to multiple reports of a man with a gun on the campus of Highland High School in the Southern California city of Palmdale, according to Los Angeles County Sheriff’s deputy Charles Moore.
The Palmdale Fire Department told CNN it has received reports of shots fired.
The sheriff’s department received the first call around 7:05 a.m.
Ricky Munoz, 23, says he dropped his two younger brothers and a friend off at the school around that time.
“About a minute later, I get a call from them saying there were gunshots,” Munoz said.
At least three nearby schools — David G. Millen Intermediate, Cottonwood Elementary and Ocotillo Elementary — were on lockdown, employees there said.
Palmdale, a city of about 150,000 people, is in Los Angeles County, about 40 miles north of downtown Los Angeles.
Developing story – more to come