A high school student in Utah left a backpack containing a homemade bomb in the lunch area of the Pine View High School in Saint George.
A message sent to parents early Wednesday referenced a "non-specific threat to our school community" as the reason for the increased police presence.
Police delivered a search warrant at the home of the young male.
According to police, the teen had been researching ISIS and showing interest in promoting the organization. "Our student was not involved and I understand the police are confident that their tech people will soon know who sent the email".
He said "he was just joking around".
Police did not describe the homemade bomb in detail but said it "had the potential to cause significant injury or death".
United States aircraft carrier approaches Vietnam for the first time since 1975
In addition to Vietnam, the United States is also tightening military cooperation with long-standing allies Australia, Japan and India.
Citing an ongoing investigation, police would not discuss the nature of the student's threat.
State police take a zero-tolerance approach to every threat that is reported, according to the police report.
The department stated, "He was then able to call in appropriate teams, such as; the Washington County Bomb Squad and Jax, the bomb-detecting K-9 from Dixie Regional Medical Center, to identify and disarm the explosive device".
The FPD became aware of a threat against Vista Del Lago High School via a text. They alerted the resident school resource officer and faculty, which led to the school's 1,100 students being evacuated to the football field for the rest of the school day...
'I think it is a shock to all of us that something like this has happened in one of our schools, ' he said. In this representational image, members of the riot police arrest a young man following clashes with demonstrators during a protest against police brutality, following the alleged rape of a black man in Paris, Feb. 23, 2017.
The lockdown was lifted and students resumed classes at about 2 p.m., after police determined the building to be safe, according to the statement.