US Air Force officials say an airman armed with a pistol has barricaded himself in a building at the Colorado Air Force base responsible for controlling all the GPS satellites.
Schriever Air Force Base spokeswoman Jennifer Thibault says the building was evacuated after the standoff began, but operations haven't been disrupted.
She says no shots have been fired and no one has been injured.
Thibault says the airman is a member of a security squadron and is armed with his own handgun. Officials haven't determined his motive. His name, rank and service history haven't been released.
The base south of Denver controls more than 60 military satellites, including those for GPS. Thibault says the airman is in a building where personnel prepare for deployments.
