Story updated Nov. 18, 2014, 11:35 p.m.
Classes at Mira Costa High School in Manhattan Beach were canceled Tuesday because of a pair of online postings regarded as a threat of violence.
The school was placed on lockdown for about an hour Monday, and security was stepped up, following an anonymous threat posted on the social media site Yik Yak.
The post read, “If you go to Costa you should watch out very closely at school today,” police said.
On Monday night, police — in consultation with school Principal Ben Dale — notified parents that classes would be canceled Tuesday, after a second threat was posted, with the author indicating that Monday was just a “drill.”
Dale sent an email to parents notifying them of the school closure, including the cancellation of a planned Scholar Breakfast and all athletic and other after-school activities.
As part of the investigation, police were reaching out to Yik Yak for assistance in tracking down who made the threatening posts.
—City News Services