Updated

Six massive fighting bulls specially bred for fearlessness charged down the narrow, slippery, people-clogged streets of Pamplona on Saturday during the first bull run of the San Fermin Festival.

One Australian man was gored slightly and one Spaniard was lucky to emerge with only a minor shoulder injury after having been tossed in the air by one of the bulls before falling into the path of another whose horns missed. Both were evacuated by ambulance.

The running of the bulls — a most Spanish of celebrations — annually combines fighting bulls, streets paved in damp cobblestones and huge doses of adrenaline, all blended with generous lashings of alcohol.

"Injuries have been relatively light," said emergency work coordinator Jose Aldaba. Altogether, seven people were treated for injuries, mostly cuts and bruises, Aldaba said.

The number of revelers swelled this year because the traditional start day, July 7, fell on a weekend. Last year, more than 200,000 tourists visited Pamplona, according to the city government. Numbers this year are likely to exceed that, said spokeswoman Edurne Elio.

Pamplona, capital of the winemaking region of Navarra, is situated immediately east of another world renowned wine area — Rioja. San Fermin is as much a feast of thanksgiving for the bounty of wine as it is a celebration of bullfighting.

It is customary for many, if not most, revelers — particularly foreigners attracted by the danger and color of the festival — to spend much of the night before a bull run drinking red wine or sangria — a wine, fruit and lemonade mix.

"I stayed up all night drinking. Thank God for espresso," said Matthew Genovese, 25, from Washington, Connecticut, in Pamplona for the first time.

Last year an American man, 31-year-old Ray Ducharme, was thrown by a young cow in an event at the bullring following the first run. He underwent a 90-minute operation at the Hospital de Navarra to reattach two vertebrae.

"They don't know what they're doing; bulls can kill," said Ruben Munoz, 24, from Madrid, who has run with the bulls during each of the last five years. "I do it for the adrenaline and because I feel liberated."

Saturday was particularly poignant for Victor Elbusto, 57, who after 40 years of running among bulls decided to give up.

"I've only been gored once, 20 years ago, and now I realize I need to give up before my luck runs out," said Elbusto.

The start of the run, normally at 8 a.m., was delayed by six minutes because police were still clearing the streets of debris and drunken crowds packing the streets after dawn.

The bulls, which are kept in an enclosure just outside the town center, are run daily during the San Fermin Festival to Pamplona's central bullring.

Along the first stretch of the 974 yards course crowds started to line the street as early as 1200 GMT.

Each of the nine days of San Fermin features bulls from a different breeder. This year the festival began with six bulls from Dolores Aguirre. The lightest weighed 1,212 pounds and the heaviest 1,356 pounds.

Injuries are common as the crowds strive to keep ahead of the bulls in narrow streets.

Since records began in 1924, 13 people have been killed. The last fatality, a 22-year-old American, was gored to death in 1995.

The San Fermin Festival dates back to the late 16th century but gained worldwide fame in Ernest Hemingway's 1926 novel "The Sun Also Rises."

On Sunday the crowd will run with Spain's most dangerous breed of bulls, the Miuras.