A 58-year-old man from Pamplona and a 73-year-old man from South Africa were admitted to the hospital with serious injuries. The man was pronounced dead about an hour later.
The town has suspended all bull-related festivities for the day.
A Canadian man is lucky to be alive after he was gored by a bull in the controversial but highly popular running of the bulls festival in Pamplona, Spain.
Runners dash along with six bulls down a narrow 930-yard course from a holding pen to Pamplona's bull ring.
A main danger of Saturday's event occurred when one of the six bulls became detached from the other five and began to attack runners following behind, rather than continue its headlong chase with its companions.
On Thursday, the bull run took just over two minutes to complete and left five runners injured.
Spanish bullfighter Miguel Abellan performs with a Fuente Ymbro ranch fighting bull during a bullfight of the 2016 San Fermin fiestas in Pamplona, Spain, Thursday, July 7, 2016. Spanish picadors or mounted bullfighters assistants get ready before a bullfight of the San Fermin Fiestas in Pamplona, Spain, Friday, July 8, 2016. Revelers from around the world arrive to Pamplona every year to take p.
The 28-year-old died after a bull's horn pierced his lung and heart during a run in the southeastern village of Pedreguer near Valencia, a spokesman for the regional government said on Saturday. The Navarra hospital said one of them had suffered a thorax wound. Both were considered to be in fair condition.
The local hospital declined to comment on the Japanese man's condition, although the local Red Cross said he had been taken there in an ambulance.
Pamplona is host to the most famous of Spain's many bull-running festivals, where hundreds of people try to outrun six charging bulls over 800 metres.
Many of Spain's towns hold summer festivals involving bulls, and several people die each year.
The festivals themselves have come under increasing pressure from animal rights groups in recent years, while many people who attend them are often injured or even killed as a result.