PAMPLONA: Thousands of daredevils fled half-tonne bulls thundering through Pamplona's streets Saturday in the first bull run of Spain's San Fermin festival, resulting in six injuries.

A 73-year-old man from Pamplona was gored in his right leg at the start of the run but the injury was not serious, the regional government of Navarra said in a statement. Five others suffered bruises or sprains in falls and were also taken to hospital, including a 26-year-old from Australia who bruised his left knee and a 21-year-old from Japan who hurt his back.

Runners, wearing traditional white clothing and red kerchiefs around their necks, tripped over each other or fell in the mad dash through the narrow, winding streets of the northern Spanish city.

Some dared to run just at arm's length from the six huge fighting bulls and six steers, glancing nervously behind at the beasts' dangerous curved horns. Others chased behind the pack, occasionally touching the bulls' sides, or cowered on the sidelines as the animals raced by.

The bulls, weighing between 520 and 590 kilos (1,150 and 1,300 pounds), stampeded through an 850-metre (2,800-foot) course from a holding pen to the city's bull ring in just two minutes, 53 seconds in a run watched by millions on television.

During the final stretch a bull knocked a runner to the ground, and one of its horns speared the collar of the man's shirt. The animal then dragged him face up for about 30 metres into the entrance of the bull ring.

Another bull's horn pierced the white trouser leg of a man who had fallen and tore off part of the material. The bull ran the rest of the course with the scrap of white cloth dangling from its horn.

“It was amazing, totally intense, scary. The build up was just crazy,” said Collin Hamer, a 28-year-old from Texas, after he completed the run.

Runners jumped up and down and did other warm up exercises as they waited behind a line of police for a firecracker to go off indicating that the bulls have been released from their pen.

The San Fermin festival features round-the-clock drinking, with bars allowed to open until 6:00 am, and loudspeakers repeatedly played an announcement in Spanish, English, French and Japanese warning people not to run drunk.

“It is something you have to experience and feel. It's a new experience, something that is impossible to forget,” said Aaron Bejar, a 31-year-old banker from Zaragoza who came to Pamplona with two friends to take part in a run.

Last year 20,500 people took part in the eight bull runs of the festival, which wraps up on July 14.

Nearly half of all participants came from abroad, with the United States, Australia and Britain accounting for the greatest number of foreigners.

Every year between 200 and 300 participants in bull runs are injured, around three percent seriously. Most are hurt after falling, but some are trampled or gored by the bulls despite increased safety measures.

The last death occurred three years ago when a bull gored a 27-year-old Spaniard to death, piercing his neck, heart and lungs with its horns in front of hordes of tourists. The bulls used in Saturday's run were from the Dolores Aguirre ranch in Seville, which has taken part in San Fermin each year since 2002.

Bulls from the ranch have caused a total of 19 injuries at San Fermin, including the six people hurt in Saturday's run.