As the annual San Fermin festival – more commonly known as the “Running of the Bulls” – kicked off this week in Pamplona, northern Spain, three men were gored during the first run Thursday. One Spaniard received serious injuries and is undergoing surgery, while two Americans were also gored in the run.

‘Running of the Bulls’ kicks off with injuries to three participants

As reported by Euroweekly News, the first event in the San Fermin festival covered the 850 meters (280 ft) course in slightly under three minutes, with hundreds of people participating.

During the run, a 46-year-old Spaniard from the Navarra region received serious injuries to his leg and head after a bull tossed him in the air.

According to hospital officials two Americans were also gored in the first run. While their identities have not been revealed, the men were aged 29 and 35. One man was gored in the scrotum, while the other received injuries to his abdomen. However, according to the hospital, neither received serious injuries. According to a report by The Local, many other people required medical treatment at the event for minor injuries and bruises during the first run of the "Running of the Bulls.".

As can be seen from a video of that event, it is not surprising that runners receive injuries.

Americans gored in the 2015 ‘Running of the Bulls’

There was a similar incident back in 2015, where two American men were injured during the “Running of the Bulls.” As reported by the Inquisitr, Mike Webster, 38, was gored in his right armpit, while an unnamed 27-year-old from California was also injured.

Neither of the runners’ injuries were life-threatening. A British man was also injured in that event.

Annual San Fermin festival in Pamplona

The “Running of the Bulls” festival runs for nine days each July and dates back to the Middle Ages. The event is dedicated to a local saint, San Fermin. The event sees hundreds of people, clad in red and white, running down the streets of Pamplona with six bulls in strong pursuit.

Author Ernest Hemingway loved the event and immortalized San Fermin in his novel “The Sun Also Rises” back in 1926. Hemingway can be seen enjoying the event below.

While obviously a dangerous sport, surprisingly only fifteen people have died while participating in the “Running of the Bulls” since it started in 1911. The latest fatality was in the 2009 festival, where a 27-year-old Spanish man was gored in the heart, neck, and lungs. Last year, 87 runners were injured with many of them trampled or gored by the bulls.

Animal activists condemn the 'Running of the Bulls'

PETA and other animal activist groups are against the “Running of the Bulls” as well as other bull fighting practices in the country. Many PETA activists were seen standing and protesting in the streets of Pamplona as the event began. A video posted to their Twitter feed shows the women standing bare-breasted with anti-bull torture messages written on their bodies. One activist jumped into the arena when a bull was killed.

While many Spaniards dub the events as being part of their “culture,” many Spanish cities and towns are now banning bull fighting and bull running events.