Álvaro Núñez's bulls raced through Pamplona at high speed during the fourth San Fermín encierro, leaving two men seriously injured. The run lasted two and a half minutes. The herd split early, creating gaps along the route and making the bulls' movements harder for runners to anticipate. Emergency services responded to nine medical incidents. One man was taken to intensive care with a bilateral pneumothorax.
The run began at Santo Domingo, where the bulls moved ahead of the cabestros. The separation spread the herd and left runners reacting quickly as the animals surged forward. At the Mercaderes curve, two black bulls collided with the barriers, putting nearby runners at risk. The cabestros later moved back in front, but falls and near-misses continued as the bulls ran along Estafeta.
On Estafeta, the spread-out herd created opportunities for close runs alongside the bulls, along with dangerous falls. Near Telefónica, a brown bull lagged behind and fell onto a group of runners. It entered the arena alone, followed by the trailing cabestros. The bulls' pace and shifting positions made the run unpredictable through to its finish.
The two most serious cases were identified as M.C.M., 65, from Castro del Río in Córdoba, and F.G.L., 63, from Zizur Mayor. M.C.M. was taken from the Plaza de Toros with chest trauma and remains in intensive care. F.G.L. suffered a fracture to his left hip on the Santo Domingo stretch and was listed in serious condition at the Hospital Universitario de Navarra.
The run contrasted with the third encierro, in which the Victoriano del Río bulls ran quickly but in a more controlled formation, with minor injuries reported. Further details appeared in coverage of the previous encierro. In the fourth run, the herd split and runners fell, leaving two men seriously injured. The incidents showed the risks that can arise when bulls and runners become separated along the route.
Álvaro Núñez's bulls were also scheduled to appear in the afternoon corrida. Morante de la Puebla was set to perform, with Borja Jiménez and Pablo Aguado also on the bill. San Fermín draws thousands of visitors to Pamplona each July, with the encierros among the festival's basic events. The morning run brought together a fast-moving herd on a crowded route, with the animals' positions changing rapidly.
During an encierro, bulls and cabestros run together through Pamplona's streets and into the arena. The herd's formation can change as the animals move along the course, affecting the space available to runners and the risk of falls or collisions. Medical teams and emergency responders attend to incidents during the event, but serious injuries remain a risk for participants.
