Spain ? A bull that broke from the pack seriously gored two American brothers, catching one on each of its horns during the running of the bulls festival in Pamplona, where both were recovering Friday in the hospital.

Lawrence and Michael Lenahan were gored simultaneously by the bull, which also injured 11 other people Thursday. It was the worst day for injuries in the nine-day festival.

“I started yelling at my brother to show him I was bleeding everywhere but he showed me he was bleeding everywhere,” said Lawrence Lenahan, a 26-year-old Air Force captain from Hermosa Beach, Calif., in a telephone interview from his hospital bed.

He was gored in the buttocks, while Michael Lenahan, 23, of Philadelphia, was injured in his leg and was recovering well from surgery at the same hospital.

The pack of six 1,300-pound bulls and six steers – intended to keep the bulls running in a single pack – disintegrated shortly after the animals set off on the course.

The run lasted 6 minutes, 9 seconds, compared with the usual length of 2 minutes because one bull separated – the most dangerous thing that can happen.