The 2017 San Fermin Running of the Bulls festival got underway Thursday in Pamplona, Spain. Take a look at the action so far.
Revellers run with Cebada Gago's fighting bulls during the second day of the San Fermin Running of the Bulls festival on July 7, 2017, in Pamplona, Spain.
The annual Fiesta de San Fermin was made famous by Ernest Hemingway's 1926 novel "The Sun Also Rises."
The most famous part of the nine-day festival is the daily running of the bulls through the historic heart of Pamplona to the bull ring.
Although the festival itself kicked off on Thursday, Friday saw this year's first running of the bulls.
Two Americans and one Spaniard were reportedly gored during the first running this year.
The bulls completed Friday's 930-yard course on cobblestoned streets in just under three minutes.
Among the rules to take part in the event are that participants must be at least 18 years old, run in the same direction as the bulls, not incite the bulls, and not be under the influence of alcohol.
Every year, between 50 and 100 people are injured during the run, including several gorings each year. Since record-keeping began in 1910, 15 people have been killed in the bull running of Pamplona, most of them due to being gored. The most recent came in 2009 when Daniel Jimeno Romero of Spain died after being gored.
A reveler drinks from a shoe as people enjoy the atmosphere during the opening day or "Chupinazo" of the San Fermin Running of the Bulls fiesta on July 6, 2017.
A reveler jumps from a fountain at Navarreria Street during the opening day of the San Fermin Running of the Bulls fiesta.
A drunk reveler falls as he was trying to climb a fountain at Navarreria Street.
Revelers hold up their red handkerchiefs during the opening day of the festival.
A reveler catches wine dropped from a balcony during the opening day.
Revelers enjoy the atmosphere from a balcony during the opening day.