It was the worst day for injuries so far. Runners were upended from behind or trampled along the 930-yard route from corral to bullring that animals and runners covered in little more than three minutes Monday.
The most dangerous moments came at the end. Dozens of runners clogged the narrow entrance to the bullring, falling over one another and blocking the passage.
The dozen fighting bulls and generally docile steers — themselves being chased by hundreds of runners from behind the pack — had little choice but to run over or through the fallen crowd.
A big black bull lifted a man up by its horns, then repeatedly raked him and others on the ground before it was distracted and walked calmly into the ring.
Among the injured was a 26-year-old man from New York who was gored in the left thigh, said Aurelio Lopez, a spokesman for Pamplona City Hall. He asked not to be identified.
Ludovico de Carlos Garcia, 24, from Paris, was gored in the right knee, Lopez said.
Five Spaniards and one unidentified person also were gored.
Ten other runners were injured, among them 50-year-old Brian White from New York, who sustained a shoulder injury.
The bull runs popularized by Ernest Hemingway in his 1926 novel "The Sun Also Rises" continue through Wednesday.
One person was gored Sunday and two on Saturday. On Friday, four runners were gored including two Americans who were released from the hospital over the weekend. In the two previous days there were no serious injuries.
Since record-keeping began in 1924, 13 people have been killed at the festival. The last fatal goring was of an American killed in 1995.