Madrid (CNN) -- A 73-year-old Spanish man was gored in the right leg on the first day of the annual running of the bulls in Pamplona and a 21-year-old Japanese runner was dragged by a bull, authorities said.
Those were two of six runners who were rushed to the hospital after the frenetic race down the narrow cobblestone streets of the old Spanish town. One of the others taken to the hospital was a 26-year-old Australian who suffered a knee injury. The Red Cross also treated 72 others for minor injuries at the scene, authorities said.
The runner from Ikeda, Japan -- whose gender was not immediately released -- was dragged by what appeared to be a bull's horn, hooked through clothing, on the pavement downhill toward the bullring, images from Spanish state television showed. The runner suffered back injuries.
There have been 15 deaths since record-keeping began in 1924 and thousands of injuries in the tradition that dates back 400 years.
Author Ernest Hemingway wrote about it in his 1920s novel, "The Sun Also Rises," also published under the title, "Fiesta," and crowds have poured in from around the globe ever since. The town has since erected a statue to Hemingway outside the bullring.
The running starts at 8 a.m. (2 a.m. ET) for eight consecutive days, through July 14, and lasts just a few minutes, from the corrals through the hard pavement of old town streets to the bullring, where the bulls face certain death against matadors later in the day.
The weekends of the fiesta traditionally see the largest crowds, when Pamplona's population of 200,000 can triple.
The race was packed on Saturday, and the run lasted just two minutes and 53 seconds to cover the 825-meter (902 yard) course.
The six fighting bulls from the Dolores Aguirre Ybarra ranch, each weighing about a half ton, stayed together for the first part of the course. At one point four of them charged ahead, as runners behind tried to dodge the two remaining bulls trying to catch up.
The Spanish man was the only one gored on Saturday. Besides the Japanese and the Australian, the other three sent to hospital were Spaniards, aged 19 to 49, who suffered shoulder, rib or wrist injuries, authorities said.
The bulls were accompanied, as usual, by a pack of six tame steers to help guide them to the bullring.
The running of the bulls is the marquee event of the week-long fiesta, named for Pamplona's patron saint, San Fermin. It includes non-stop activities, including concerts, parades and amusement park rides, that aim to appeal to all ages. The event is huge boon to the local economy.