Four people were severely injured at a bull-run in the streets of Pamplona during the San Fermin festival. The bull-run - in which the bulls weigh in at just over 500 kg (1,102 pounds) - often results in numerous casualties and sometimes even death as thousands of people are chased by the animals through Pamplona's streets. 15 people have been killed in the bull runs since official counting started in 1911, with the last person dying in 2009.