Revellers take part in Spain's bull-running festival in Pamplona

Revellers from around the world arrive in Pamplona every year to take part, during the eight days of the running of the bulls. (Photo: AP)

People celebrate during the launch of the 'Chupinazo' rocket, to celebrate the official opening of the 2017 San Fermin Fiestas, in Pamplona, northern Spain, Thursday, July 6, 2017. (Photo: AP)

Revellers hold newspapers as they sing a song to San Fermin on Santo Domingo street ahead of the first running of the bulls at the San Fermin Festival, in Pamplona, northern Spain, Friday, July 7, 2017. (Photo: AP)

Members of the San Fermin Comparsa Parade get ready to take part on a procession at the San Fermin Festival, in Pamplona, northern Spain, Friday, July 7, 2017. (Photo: AP)

A member of the San Fermin Comparsa Parade dressing as a horse, called as Zaldiko, dances on the street during a procession at the San Fermin Festival, in Pamplona, northern Spain, Friday, July 7, 2017.(Photo: AP)

Revellers run in front of Cebada Gago fighting bulls during the first running of the bulls at the San Fermin Festival, in Pamplona, northern Spain, Friday, July 7, 2017.(Photo: AP)

A boy cries next to a member of the San Fermin Comparsa Parade, during a religious procession at the San Fermin Festival, in Pamplona, northern Spain, Friday, July 7, 2017.(Photo: AP)

At least two people have been gored and many injured during the first running of the bulls of this year's San Fermin festival, medical officials in the northern Spanish city of Pamplona said. (Photo: AP)