PORTLAND, Maine (WGAN) Police say Portland High School was in lockdown Tuesday morning due to what turned out to be an unfounded threat.

Police said the building was locked down for an hour around 10:20 A.M. Tuesday. Dispatchers received a call that someone was in the school with a gun. The building was cleared and the school was re-opened, and there was no credible threat found. Police believe the call was a hoax.

Police are working to identify the caller and are asking anyone with information to contact them.