Monday was a tense day at one of our Central Texas High Schools, as Groesbeck police stayed on campus through a lockdown of the campus.

KXXV.com reports that a threat came into 9-1-1 around 2 p.m. made by an unknown individual who said they intended 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 its 911 services. While the caller didn't specifically name 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.