A U.S. military official confirmed to NBC News that a service member is in custody after making a threatening phone call.
The official said the individual placed a call to Fort Hood, threatening to harm people.
The incident is under investigation.
Fort Hood officials have not released any further information.
The incident happened just one day before the first anniversary of an on-post shooting that left four people dead and more than a dozen injured.
NBC 5 will update this story with more information as soon as it's available. As this story is developing, elements may change.