Air Force officials say an airman with a gun has surrendered to authorities after barricading himself in a building at the Colorado Air Force base that controls GPS satellites.

Schriever Air Force Base spokeswoman Jennifer Thibault says the building was evacuated after the standoff began Monday. Officials said the situation was "resolved" as of 8 p.m.

There were no reports of injuries or disruptions in operations.

The airman was in a building where personnel prepare for deployments. Control rooms for satellites are in a separate area.

Thibault says the airman is a member of a security squadron and was armed with his own handgun. Another spokeswoman says the man faces a discharge over a matter in civilian court, but she didn't have details.

His name hasn't been released.