MANHATTAN BEACH ( — Mira Costa High School in Manhattan Beach was placed on lockdown Monday due to an unspecified threat, the third time in the past week that the school has been targeted by a threat.

Principal Ben Dale notified parents via email about the threat at the school at 701 S. Peck Ave., and he said the Manhattan Beach Police Department had been notified.

“We have received another threat this morning that we are investigating,” Dale’s email said. “MBPD is here with us conducting a search. Students are in a shelter in place, meaning they will be in classrooms, safe with their teachers, until we have concluded our search.”

On Friday, Mira Costa and nearby Pennekamp Elementary School were closed for the day “due to a specific threat,” but authorities later that day reported that “no suspicious activity exists” at either campus and all city schools would be open Monday, with a continued police presence.

On Dec. 7, a “non-specific” threat prompted authorities to evacuate Mira Costa High School and cancel classes for the day, police said. A search of the campus turned up nothing dangerous, however.

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