Pamplona, Spain ? Tens of thousands of cheering, champagne-soaked revelers packed the central streets and plaza of this northern city Saturday to kick off Spain’s most famous fiesta the bull-running festival.

To the cries of “Viva San Fermin!,” town councilor Roberto Jimenez ignited the traditional “chupinazo” firecracker in the city’s main square to officially start the San Fermin festival, popularized by Ernest Hemingway’s 1926 novel “The Sun Also Rises.”

Festival participants sing and dance in the streets after the chupinazo, or official opening of the 2002 San Fermin festival in Pamplona, Spain. The festival, Los

“Los San Fermines,” held since 1591, attracts tens of thousands of foreign visitors each year for nine days of revelry, morning bull-runs and afternoon bullfights.

“For me, Pamplona is the last stop on the romantic road, ” said Ray Mouton, a former lawyer from New Orleans who has been coming since 1970. “San Fermin is all about generosity. The fiesta is all about the heart.”

Mouton says he hasn’t run with the bulls since 1998 when he was trampled by a fellow runner. But he says he’ll be back out there today for the inaugural run.

This year, however, one group served notice that not everyone thought the fiesta, in which 50 bulls are almost certain to be killed in afternoon bullfights, was something to be celebrated.

A day before the start, some two dozen members of the Ethical Treatment of Animals, a U.S.-based international animal rights group, ran naked through the streets of Pamplona with their bodies painted with slogans like “let bulls die in peace,” calling for an end to bullfighting.

The mostly young activists from various European countries and the United States said they wanted to draw attention to the suffering of the bulls during the so-called ‘encierro,’ the near three-minute charge through the old city for which the San Fermin festival is famous.

On Saturday, however, there were no signs of protest.

Wild cheers erupted from the thousands of people, most dressed in the traditional white shirts with red neck scarves, crammed into old quarter’s narrow streets as they doused each other in champagne, danced and sang local folk songs. Some hurled eggs, flour or cacao at each other and then embraced and kissed whoever was nearest.

“I came here to test my bravery,” said first-timer Terry Bunsen, a 31-year-old publicist from London. “This is better than I expected. It’s mad, totally mad. I now realize that it’s more about the party than the bull-run.”

Dozens of people waved the green red and white Basque flag in support of independence for the neighboring Basque region.

This morning, and after virtually 20 hours of nonstop partying, hundreds of the bravest or most reckless people will test their mettle and fitness in a three-minute dash to the bullring pursued by six prime fighting bulls and a handful of guiding steers.

The run is a 902-yard stampede from the corral where the bulls are kept to the outdoor bullfighting arena where they will be invariably killed by matadors later in the day.

The spectacle is repeated each day until July 14 and is broadcast live on Spanish television. But injuries are always numerous, as the large crowds jostle for space to dodge the bulls sharp horns and death is always a possibility.

A 22-year-old American, gored to death in 1995, was the last fatality in the run. He was the 13th runner to die since records began in 1924.