UPDATE (1:15 p.m.): Dartmouth Police posted the following on their Facebook page:

After a thorough review of the low-level threat, as well as an exhaustive search by specialized K-9's, the shelter in place at DHS has been lifted, and normal activity has resumed.

We would like to take this opportunity to thank the community for not only working hand-in-hand with us throughout the day but also for not feeding into (and spreading) the rumors often associated with incidents such as this one.

We would also like to thank all of the first responders who assisted us with this investigation, in particular, the Massachusetts State Police, Fall River Police Department, Quincy Police Department, and the Bristol County Sheriff's Department.

DARTMOUTH — Police are investigating after what is believed to be a threat was discovered at Dartmouth High School.

Dartmouth Police responded to the high school before 11 a.m. after the threat was reported.

Students and staff have been told to shelter in place as a result of the discovery.

Police say the threat is classified as "low-level."

Parents and guardians of students were made aware of the threat via text message shortly after 11 a.m.

Emergency personnel are at the high school and are working to determine the validity of the threat.

Police did not disclose the nature of the threat or how it was made.

This story will be updated.