After sevweral minutes, bull ring runners were able to tie a rope around the bull to bring it under control, reports CBS News corresondent Charles D'Agata. Later, the animal was taken away by crane and killed.
The incident occurred Wednesday at the Tafalla arena in the northern region of Navarra, during a spectacle in which mostly young people try to get a bull to charge at them so they can dodge it with slick movements of their bodies. Unlike standard bullfights, the bulls are not killed in these events.
On Wednesday, the bull had already attempted to jump into the stands twice. After damaging a horn, he was about to be returned to the corral and replaced with another one when he tried a third time and succeeded. Officials said the bull was about to be removed because -- it was under-performing.
A regional government statement Thursday said three people remained in hospitals in the regional capital of Pamplona, best known for its annual San Fermin running of the bulls festival.
The injured included a 10-year-old boy who was in intensive care after the bull reportedly fell on him. Another man was gored in the back and was said to be in stable condition.
In all, 40 people were treated, mostly for minor injuries.
The regional government said the crowd was made up largely of young people, and most were able to get away from the bull quickly, avoiding a greater number of injuries.
CBS Newss correspondent Jeff Glor recapped the incident:}
D'Agata points out the debate over whether bullfighting should be banned is picking up steam in Spain -- a furious argument that pits animal rights against age-old tradition.
Catalonia became the first region to outlaw the "sport" last month.
It's very rare for a bull to leap out of the arena and into the stands.