It's was a tense day at one of our Centra Texas High Schools today as Groesbeck police stayed on campus through a lockdown at the school on Monday.

News 10 reports that a threat came into 9-1-1 around 2 p.m. made by an unknown individual threatening to 'shoot up' the school. The caller then hung up the phone.

Police have looked into the number the call came from and found what appears to be a deactivated cell phone that was still able to access it's 911 services. While the caller didn't specifically say 'Groesbeck' High School, the call was received on a Groesbeck cell tower. This was enough to put police into action.

As a precaution, the police notified GISD and locked down the school. After some investigating the lockout was lifted after police felt the threat was no longer credible.

The "lockout" was lifted shortly before 3 p.m. and police stayed on campus for the rest of the day.