OMAHA, Nebraska: A teenager opened fire with a rifle at a busy department store in the US Midwest, killing eight people in an attack that made holiday shoppers run screaming through a mall and barricade themselves in dressing rooms.

The young shooter, who left a note predicting, "Now I'll be famous", wounded five others, two critically, then took his own life on Wednesday.

Witnesses said the gunman sprayed gunfire down on shoppers from a third-floor balcony of the Von Maur store using what police said was an SKS assault rifle they found at the scene.