The bull runs are one of the most crowded events of the week-long San Fermin festival, which was immortalised in Ernest Hemingway’s 1926 novel “The Sun Also Rises”.
“The number of people being treated at the emergency ward of Navarra hospital complex has risen to five, three because of bull horns,” the Navarra regional government said on Twitter.
Authorities said in a statement that those hurt included two US citizens, aged 23 and 46, and a Spaniard, who was injured in his left thigh. Local media reported one of those gored was in serious condition.
The daily runs see hundreds of people dressed in white shirts and red scarfs, sprint with bulls through narrow streets to the city’s bull ring, where the animals are killed by professional matadors in an afternoon bullfight.
The festival, which also involves religious processions, concerts and all-night drinking, attracts thousands of visitors from around the world.
Bull fights and bull runs are a traditional part of summer festivals across Spain.
Anyone over the age of 18 can participate in the Pamplona runs though authorities warn of the risks. Since 1911, 16 people have been killed in the event, the last one in 2009.