Police in Southern California on Friday investigated threats made against school campuses and dispatched extra patrols out of an "abundance of caution" a week after a gunman shot and killed 20 first graders and six adults at a Connecticut elementary school.
Officials said they did not think the threats were credible, but they're taking no chances.
The moves came on a day when authorities said a 14-year-old student brought a gun and 50 rounds of ammunition to Fresno High School as officials investigated a Facebook threat "to shoot the place up." Also, a 61-year-old man from Oceanside was arrested Friday after officials said he left a threatening message for staff at Laurel Elementary School.
Los Angeles County Sheriff’s Department deputies were dispatched after 9 a.m. Friday to Diamond Ranch High School in Pomona, where administrators said they received a threatening phone call. The campus of 1,800 students was placed for four hours on lockdown, a process the campus had practiced earlier in the week.
"We turned off the lights, locked the doors, barricaded the doors for our safety," said senior Ryan Lizardo.
Sheriff's Lt. Chris Blasnek of the Walnut/Diamond Bar Station said the threat was determined not to be credible.
"We take all threats seriously and will continue to work closely with school administrators to do all we can to ensure the safety of students and teachers," he said in a press release.
Meanwhile, extra deputies were called out to La Mirada High School as a precaution because the school received “unsubstantiated rumors of a shooting within 72 hours," officials said.
Orange County Sheriff's Department deputies sent patrols to Dana Hills High School after a student posted on Facebook that he didn't want to go to school because he didn't want to get shot, officials said.
Police were expected to be posted through the day at South Pasadena High School where authorities said a female student called police Thursday night, saying a male in a hoodie approached her at school and said, “don’t go to school tomorrow. There is going to be a shooting.”
The shooting at Sandy Hook Elementary School in Newtown, Conn., on Dec. 14 prompted school officials across the country to pay close attention to student and parent emotions to the tragedy and reinforced the importance of safety.
In addition to police, school administrators have dispatched counselors to help students cope.
Police and staff have been reviewing and updating school safety plans, including lockdown procedures, and have been reminding parents and staff to close and lock gates behind them.
Joel Shapiro, the superintendent of the South Pasadena Unified School District, said plans are moving forward to construct fences at Monterey Hills Elementary and South Pasadena Middle School as soon as possible.
“I want to assure you that our principals, teachers, and other staff are well trained and are doing everything they can to make safety their highest priority,” he said in a message sent to parents earlier this week.
Los Angeles Police Department Chief Charlie Beck announced this week that officers will visit all of the 740 kindergarten, elementary and middle schools in the city at least once daily when children return to school in January.
LA police also announced that an annual gun buy-back initiative, in which owners can anonymously trade in weapons for grocery store gift cards, will be held the day after Christmas instead of in May.
The actions come as this week police arrested a 24-year-old man in connection threatening to harm children at multiple elementary schools on his Facebook page in what he allegedly said was a joke. The LA County District Attorney's Office declined to press felony charges against the man, saying the threats did not specifically target a school or an individual.
On Saturday, shoppers were sent running for cover when a gunman opened fire outside a mall in Newport Beach, south of Los Angeles, firing some 50 shots into the air and at the ground, re-loading several times. Nobody was injured in the incident, and the gunman was detained by police without resisting.
NBC staff and wire services contributed to this report.