(CNN) Three New York teenagers were arrested Thursday after being accused of planning to build a bomb and detonate it at a high school on Long Island.

Connetquot High School in Bohemia, New York, was evacuated for roughly 30 minutes on Thursday morning while the three boys were arrested, Suffolk County Police Commissioner Geraldine Hart told reporters.

The boys, all 16 years old, have not been identified by police.

Police said the three were overheard discussing plans to build a bomb while on a school bus ride home Wednesday afternoon. Multiple other students reported the conversation to school administrators, who notified the police.

"The department takes these threats extraordinarily seriously," Hart said to reporters. "While the majority of these instances do not rise to the level of violence, we treat all of them as if they can be executed."

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