A Hudson Valley high school was placed on a shelter in place yesterday and a student was arrested following alleged threats made on social media.

On Thursday, the Bureau of Alcohol Firearms and Explosives notified the Town of Lloyd Police Department in regard to a threat made Twitter. The threat referenced the Norwegian terrorist Anders Behring Breivik, officials say. Breivik was convicted in 2012 of a terrorist attack that killed 77 people in Norway.

According to a Facebook post from Highland Central School District, a student allegedly made a disturbing post on social media on Wednesday. As a result, Highland High School had a shelter-in-place activated for Thursday as police investigated.

The Town of Lloyd Police initiated an investigation an alleged a 15-year-old Highland High School student made the threat. The student was found at the high school.

The 15-year-old's parents cooperated with detectives and searches were conducted of two separate homes where the juvenile resides in the Town of Esopus and the Town of Plattekill, police say.

Although the teen was found at Highland High School, no threats were made in regard to the high school or any other specific location, according to the Ulster County Sheriff's Office.

The investigation revealed that the threat posed no immediate danger and the searches conducted by police did not produce any weapons or items of concern, officials say.

The shelter-in-place was lifted at Highland High School around 1 p.m. The 15-year-old teen was charged with an offense that if committed by an adult would be the crime of making a terroristic threat, class D felony, police say.