Participants hold red scarves as they celebrate the 'Chupinazo' (start rocket) to mark the kickoff of the San Fermin Festival, in front of the Town Hall of Pamplona, northern Spain, on July 6, 2017.

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. The festival, locally known as Sanfermines, is held annually from July 6 to 14 to commemorate the city's patron saint, San Fermin. Many of the visitors physically participate in the highlight event, the running of the bulls, where they attempt to outrun the bulls along a route through the narrow streets of the old city.