Bomb threats are on the rise in New Jersey's schools.

The state's Homeland Security and Preparedness Office says students have been evacuated at least 61 times this school year, a 27 percent increase over last year.

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There were 19 evacuations in April, with an increase after the Boston Marathon bombings on April 15. Most took place on Mondays and Thursdays and were usually triggered by a note or graffiti.

Officials estimate it has cost $2 million to respond to the threats, which have turned out to be false.

Montville School Superintendent Paul Fried tells The Record newspaper he has asked police and parents to talk to children about the severity of false alarms.

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