Authorities at the U.S. Army base at Fort Hood, Texas have issued an order directing all base personnel to take shelter.
The order was sent late Wednesday, as reports circulated of an ongoing criminal shooting event on the sprawling base near the city of Waco.
A short while later, a brief military statement confirmed injuries, but offered no other details. The shooter or shooters are said to be at large on the base.
Emergency crews are on the scene.
Fort Hood was the scene of a mass shooting spree in 2009. Thirteen people were killed and more than 30 others wounded when an Army psychiatrist opened fire on personnel.