The festival was immortalised in Ernest Hemingway's 1926 novel "The Sun Also Rises" and it attracts thousands of visitors from around the world.
Three men were gored during the opening run of Pamplona's bull-running festival, the Red Cross said on Friday, with one other reported injury during the 875-metre run through the northern Spanish city.
The first bull run, which traditionally draws the largest number of participants, is on Thursday. A run takes on average just under four minutes. Dozens of daredevils are hospitalised each year. Most of the injuries are not caused by bull horns but by runners falling, or being knocked over and trampled by the animals. Fifteen people have been killed in the bull runs since modern day records started in 1911.
Each day at 8:00 am hundreds of people race with six huge bulls, charging along a winding, roughly 875-metre (more than half a mile) course through narrow streets to the city's bull ring, where the animals are killed in an afternoon bullfight. The bravest run as close to the tips of the horns as possible without being gored.
The nine-day festival in honour of the patron saint of Spain's northern Navarra region - San Fermin - dates back to medieval times it involves religious processions and all-night partying in addition to the hair-raising daily bull runs that have made it famous.
is/at (rtr, afp)