Six massive fighting bulls slipped on morning dew-dampened cobblestones and tossed people aside as they ran with them on the half-mile course through the narrow city streets to the bull ring.
The Navarra government said a 26-year-old Colombian man was taken to Virgen del Camino hospital with a gored right buttock, a 33-year-old man from Ghana suffered a broken jaw and a Barcelona man, 55, will require plastic surgery on his right ear.
In minor injuries, a 29-year-old Madrid resident broke his nose and a 26-year-old from Lesaka fractured his left wrist, the government said.
Minutes before the run began, police cleared the streets of about a half-dozen animal rights protesters.
The run - the sixth in the weeklong adrenalin and alcohol-fueled annual festival
- was quick, lasting less than three minutes despite an unusually large weekend crowd in which serious bull running aficionados were joined by revelers.
At least three of the fierce animals from the renowned Dolores Aguirre Ybarra ranch fell, despite being accompanied by guiding steers and staff-carrying bullherds.
One runner was caught between the horns of a bull, hit first by its left horn then the right one, before being nudged to the side. That runner avoided a goring.
Several people were caught in a crush of festivalgoers and forced to dive for cover as the bulls approached, suffering cuts and bruises in the process.