PAMPLONA, Spain – The penultimate bull run of Spain’s San Fermin festival left at least 23 people injured Saturday, when thrill-seekers fleeing the beasts were crushed at the narrow entrance to the bullring, officials said. An American citizen from Ohio was one of two runners gored. As the huge animals thundered into the entrance of the tunnel, they were blocked by a mound of dozens of people who had fallen and were piled on top of one other.

One bull that had fallen before the entrance got up and charged into the clogged passageway. Two steers jumped over the pile of people as they began to get up and flee.

“I felt anguish and helplessness for the people trapped there, not knowing how to get out,” said Jesus Lecumberri, 20, a student with several years’ experience running at Pamplona and other bull-running festivals.

Lecumberri said he had charged in to the entrance alongside the first bull, but saw the pileup and quickly dived into a ground-level hatch built into the passage specifically to provide an escape route from situations like this. A gate normally used to let regional police into ringside positions had been accidentally pushed wide open by a flood of runners, causing an obstruction for others trying to enter the main arena, Interior Ministry regional spokesman Javier Morras said.

“We all know that alley is a funnel and a critically dangerous point at the entrance to the ring,” Morras said. “Pileups there are one of the biggest risks that can occur in the running of the bulls,” he said.

The blockage ended after attendants managed to let the beasts escape through a side door. Javier Sesma, a health spokesman for Navarra province, said two of the 23 injured people were gored by bulls and that the others were hurt in the stampede.