The 875 metre morning run throught the cobbled streets of the Navarra capital lasted 2 minutes and 40 minutes and featured fighting bulls from the Nuñez del Cuvillo ranch.
Initial reports suggested that two runners received gorings; the first in his right leg as he was caught by a horn on the Santo Domingo stretch in the early part of the run and the second occurred at the top of Estafeta where a runner was gored in his groin region.
WATCH: The seventh run at San Fermin 2017
In addition several other runners, at least four, were treated for injuries including one who sustained a head injury. All those injured were Spanish, according to authorities,
The final day of the fiesta, which was made famous by Ernest Hemingway and now attracts more than one million revellers to the city, takes place on Friday.
Earlier in the week, three people were gored, including two Americans. Since record-keeping began in 1924, 15 people have been fatally gored at the festival. The last was Spaniard Daniel Jimeno in 2009.