Pamplona/Iruña's San Fermin festival's "chupinazo"

A small, ceremonial rocket hisses over a teeming sea of people and bursts in a cloudless sky to signal the start of Pamplona/Iruña's famed running of the bulls festival.

Thousands of revelers clad in the traditional red and white colors of the San Fermin festival scream with delight and jump up and down as one of the world's most popular festival gets underway. The daredevil part of the festivities, crowds of people making a mad dash alongside fighting bulls, begins July 7th with the first of eight such runs.

Red and white confetti tosses from rooftops in the town square fluttered through the air as the first of more than dozen small rockets is fired from a balcony overlooking the multitude. The first of the rockets, known as the "chupinazo", officially launches the centuries-old festival named for Pamplona/Iruña"s patron saint and its week of nonstop street parties.

Down below in the crowd, people are caked with a mix of flour, handfuls of it are chucked everywhere as a messy party favor, and red wine.

The runs are held early each morning with streets often moist and slippery with dew. Thrill-seekers from around the world run alongside six bulls and six steers meant to keep the former in a pack as they rumble along a 850-meter (930-yard) cobblestone course from a holding pen to the city's bullring.Once in the ring, the bulls face matadors and death in the afternoon.

The festival was made internationally famous by Ernest Hemingway's novel "The Sun Also Rises." Since record-keeping began in 1924, 13 people have been killed during the runs. The last was a 22-year-old American, Matthew Tassio, who was gored to death in 1995.