PAMPLONA, Spain — Several people were trampled but not seriously hurt Wednesday as thousands took part in the first bull run of the San Fermin festival, dashing along the slippery cobblestone streets of this ancient city in northern Spain, bulls right behind.

"Running ahead of bulls is life and I wanted to feel alive," said Ray Sabbatini, 36, of Wisconsin, who suffers from multiple sclerosis and was accompanied by his friend Dennis Rodman, the retired NBA star.

"I wasn't afraid," said Rodman, wearing sunglasses and still looking muscular, tattooed and larger than life as he ate ox tail stew at a cafe following the bracing two-minute run. "I like strong emotions."

None of the runners was gored, and only four injuries were serious enough to require treatment. Two bulls skidded and fell, as did some runners after a night of rain left the streets slick.

"So far there aren't serious injuries, but there's a lot of people with little experience and we have a lot of work," said Mikel Eusa of the Red Cross.

Policeman Jose Ramon said he prevented two Australians from taking part out of concern for their safety: "They had a lot to drink and I didn't let them by."

For all the hype, the actual run is just 825 metres and lasts little more than two minutes from the starting corral to the finish in the bull ring.

But for many of the thousands of tourists from all over the world, it's the sprint of their lives.

"I didn't sleep all night," said Tom Langhurst, 20, a student from Swisher, Iowa. "I was very nervous but now I feel I'm on top of the world."

Sonia Laje, 23, of Freiburg, Germany, pulled out at the last minute. "I decided not to run. Too fearful," she said, blushing.

Runners dressed in the traditional white shirts and trousers with red scarves. Many ran ahead of the five bulls from the Torrestrella ranch, staying as close as possible without risking getting gored.

"It's pure adrenalin. I can't live without it," said Pascual Rubert, a car mechanic from Castellon, Spain.

Others ran alongside, sometimes with a hand on the bull's rump for balance. Then there were those who stayed safely behind, sharing the thrill if not the actual danger.

The bull runs continue daily, starting at 8 a.m., through July 14.

The San Fermin festival, renowned for its all-night street parties, dates back to the late 16th century. But it gained worldwide fame from Ernest Hemingway's 1926 novel, The Sun Also Rises.

The bulls were originally run through town to get them to the ring for bullfights held each afternoon of the festival. But over the years, it has become popular to run in front of the beasts.

Overcrowding has increased the danger of the event. Since record-keeping began in 1924, 13 people have been killed at the festival. The last fatality was an American killed in 1995.