NEWTOWN,  Conn. (NBC) — Sandy Hook Elementary School students have been sent home for the day after a bomb threat forced an evacuation on the sixth anniversary of the massacre that killed 20 first-graders and six educators.

Newtown police said a bomb threat was called in around 9 a.m. Friday and the school was evacuated.

Lt. Aaron Bahamonde said the threat is not believed to be credible, but they are taking it seriously and will investigate fully.

No one was hurt and no one was in danger, he said.

There’s a heightened level of anxiety in town on the anniversary and the school superintendent decided to cancel remaining classes, according to Bahamonde.

Police said this not believed to be related to the bomb threats made nationwide Thursday.

Newtown did receive two other threats in Newtown yesterday.

The school where the shooting happened on Dec. 14, 2012, was knocked down and a new building was constructed at the same site.

Moments of silence were observed in Newtown and other places Friday morning in memory of the victims.