A video has been released by People for the Ethical Treatment of Animals (PETA) showing the moment someone jumped into a bullring at a bullfight during the San Fermín festival.
The footage shows two members of Vegan Strike Group jumping the wall of the bullring just after a matador stabs a bull in the back of its neck as it lay prone at the end of a bullfight in Pamplona, Spain.
In the graphic clip one off the men runs over to shield the bull as it lay bleeding and dying, while another man, who had the message Basta Corrida, which translates to "Stop Bullfights", painted on his body, holds a sign saying "Bullfighting Is Torture".
The two are then hauled away by officials. Be warned that the video is graphic and may be very upsetting.
Peter Janssen of Vegan Strike Group said: "The bull was terrified and in excruciating pain – we couldn't leave him to die alone. We represent the majority of people around the world, who are calling for an end to this cruel event."
PETA Director, Elisa Allen, said: "Bullfighting is an abusive, archaic spectacle that has no place in a civilised society.
"PETA commends these brave protesters for reminding spectators that tormenting and killing animals for so-called 'entertainment' is contemptible."
It comes as two Americans and a Spaniard have been gored during the first running of the bulls of this year's San Fermin Festival, medical officials said.
A 46-year-old Spanish man was undergoing surgery for serious injuries to his head and leg after he was gored and then tossed by a bull.
Hospital officials said two men from the United States had also been gored during the run but their injuries - in the abdomen for a 35-year-old man and in the scrotum for a 29-year-old - were not considered serious.
More runners were treated on the spot for bruises, a Red Cross spokesman said, as two of the animals separated from the other four in the pack on their way to Pamplona's bullring.
They completed the 850m course through cobbled streets in just under three minutes, a speed that is considered average for the run.