Web threat shuts Calif. school for 2 days

MANHATTAN BEACH, Calif. - Classes at a Manhattan Beach high school were canceled Wednesday for a second straight day as police investigated online postings regarded by authorities as threats of violence.

The five messages posted via the anonymous social media application Yik Yak prompted police and officials at Mira Costa High School to agree to close the campus on Tuesday and Wednesday.

The school was also locked down for about an hour on Monday, when the postings began.

A student spotted the first message and reported it to a teacher, said Officer Stephanie Martin.

CBS Los Angeles reports the first message said, "If you go to Costa you should watch out very closely at school today."

That message was followed by others saying, "Nice try Costa. Today was just a drill."

"Almost every school shooter left a warning before committing the crime and everyone just ignored them, just remember," another read.

"Tomorrow at 2. be ready Costa. You're going on lockdown."

The final message said, "If you go to Costa you should watch out very closely on Wednesday."

Officer Martin said investigators were working with officials at the Yik Yak social media site to identify a suspect and make an arrest.

The social media application reportedly uses GPS to determine a user's location and displays anonymous posts within a 1.5-mile radius.

The school was expected to be open again Thursday, schools Superintendent Michael D. Matthews said in an email.

"Students can expect to have counselors available, to have an increased police presence on campus and to go back to high quality instruction in the classrooms," Matthews said.