Two American brothers seriously gored during a bull run in the northeastern Spanish city of Pamplona were recovering at a hospital Friday.

Lawrence Lenahan, 26, of Hermosa Beach, California, and his brother, Michael Lenahan, 23, of Philadelphia, were gored Thursday by a bull who strayed from the pack. Thirteen people were injured and seven were gored, including the Lenahan brothers and another two men who were seriously injured.

Michael Lenahan, a sales executive for General Mills, was injured shortly before making it to the bullring — the end point of the daily runs. The bull's horn broke through the skin on his right shin. The moment, caught on film, made the front page of several Spanish newspapers.

The older Lenahan suffered an 8-inch wound in the left buttock after a dangerous sharp right turn in the course, which he described as a "dead man's curve".

"I remember looking back and thinking I was in trouble," said Lawrence Lenahan, an Air Force captain, in a phone interview with The Associated Press from his hospital bed in Pamplona. His brother also remains hospitalized after undergoing surgery.

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 through the narrow cobblestone streets of Pamplona.

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 during a bull run.

The other runners who were gored were from Poland, Norway and Spain, with ages ranging from 23 to 50.

Friday's run, which lasted 2 minutes, 42 seconds, occurred with few complications though several people sustained bruises and other minor injuries.

The San Fermin festival in Pamplona, renowned for its all-night street parties, dates back to 1591. It gained worldwide fame in Ernest Hemingway's 1926 novel "The Sun Also Rises."

Since records began in 1924, 13 people have been killed in the runs. The last fatality, a 22-year-old American, was gored to death in 1995.