A Million Join Pamplona's Annual Bull-Running Festival

Jubilant crowds filled Pamplona's main square on July 6, 2016 as the traditional "Chupinazo", a firecracker in the shape of a rocket, burst into the sky, marking the beginning of the northern Spanish city's week-long San Fermin festival.

The annual Fiesta de San Fermin, made famous by the 1926 novel of US writer Ernest Hemmingway entitled 'The Sun Also Rises', involves the daily running of the bulls through the historic heart of Pamplona to the bull ring.

A woman drinks before the Riau-Riau procession of the San Fermin Festival on July 6, 2016 in Pamplona.

The Riau-Riau is a procession held in which members of the city council parade from the City Hall to a nearby chapel dedicated to Saint Fermin.

People celebrate at City Hall Square during the beginning of San Fermin's festival. At noon, the 'chupinazo' was fired from the City Hall's balcony in an marking the beginning of the nine-day 'fiesta'.

Fuente Ymbro fighting bulls take the Estafeta corner during the first running of the bulls at the San Fermin festival in Pamplona, on July 7.

Daredevils test their speed and bravery by racing with six fighting bulls along a half-mile long street course to the city's bull ring. The bulls then face matadors and almost certain death in afternoon bullfights.

Crowds run with Fuente Ymbro's fighting bulls along Estafeta Street during the second day of the San Fermin Running of the Bulls festival on July 7.

Bull runs, or "encierros," as they are called in Spanish, are a traditional part of summer festivals across Spain. Dozens of people are injured each year in the runs, most of them in falls.

People dance and sing during the Riau-Riau procession of the San Fermin Festival on July 6, 2016 in Pamplona.

Revelers hold up their red handkerchiefs during the 'Chupinazo' July 6.

Thousands of people waving the festival's traditional red neckerchief jammed the square down below and immediately began jumping and screaming "Viva San Fermin!"n after the 'chupinazo.' 

The firecracker also signaled the moment to don the neckscarf, part of the festival garb along with white trousers and shirt.

Spanish mounted bullfighter Pablo Hermoso de Mendoza performs during a horseback bullfight at the San Fermin Fiestas, in Pamplona, on July 6.

A reveler is tossed as he tries to get a snapshot next to a brave cow in the bullring during a daily amusement event after the first running of the bulls in the San Fermin fiestas on July 7.

People enjoy the 'Gigantes' and 'Cabezudos' traditional street parade, as part of the San Fermin fiestas on July 7.

Alberto Virgen, from Los Angeles, shows his bull skull tattoo with the dates of the birth and death of his grandfather, after he survived the first running-with-the-bulls in Pamplona's fiesta de San Fermin, on July 7.

A reveler is chased by a Fuente Ymbro's ranch fighting bull in Pamplona, on July 7.

A wounded runner is moved to be treated after the first bull run of San Fermin on July 7. At least four people were injured during the bull run. Thursday's run lasted 2 minutes, 28 seconds.

 Many people suffered falls and were trampled on by the beasts or other runners. In one incident, four bulls crashed into a bunch of participants close to the end of the race, and several people narrowly missed being gored.

People carry an image of Saint Fermin during a procession on the second day of the San Fermin festival on July 7.

Runners sprint alongside Fuente Ymbro fighting bulls at the entrance to the bullring during the end of the first running of the bulls at the San Fermin festival, on July 7.