A Cebada Gago bull charges into runners during the first running of the bulls at the San Fermin festival in Pamplona, northern Spain, July 7, 2017.
Hospital officials said the Americans' injuries were not as serious, with one being gored in the abdomen, while the other had been gored in the scrotum.
According to local media, a 35-year-old identified only as EH sustained a chest wound, while his USA compatriot, 29-year-old AP, was gored in the scrotum. A man from Ireland, 39, was also hurt.
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They completed the 930-yard (850-metre) cobbled-street course in just under three minutes, a speed that is considered average for the run.
The animals were from cattle breeder Cebada Gago in Andalucia, renowned for rearing risky bulls responsible for the most injuries in the history of the week-long San Fermin festival.