Academy of Notre Dame closed Tuesday after threat discovered

TYNGSBOROUGH, Mass. — Officials say the Academy of Notre Dame in Tyngsborough will be closed for school Tuesday after a threat directed at African Americans was discovered.

Tyngsborough Police are investigating the threat, which was found in a typed letter in the girls' bathroom at the school. The letter specifically referenced Tuesday's date.

>> Scroll down to read the full letter sent out to parents

"We do not believe there is a credible threat against the school, but we are conducting an active and ongoing investigation at this time," Howe said.

In a news conference Tuesday morning, police said the threat was very general and mentioned something big happened. Police said they were confident the threat came from a student.

Police said they would be consulting with the District Attorney to determine what charges a potential suspect or suspects could face.

Other racist posting targeting the upper school have appeared over the past few months on Instagram and Twitter, according to Police Chief Richard Howe. Police first started investigating the posts in February, and they said they have reached out to Facebook officials.

The posts seem to target five or six students, police said Tuesday. Police believe that Tuesday's threat is related to the social media posts. The suspect is posting pictures of the targeted students online and using the name "Rebuild NDA".

Full letter sent out to parents: