At least three people were gored Sunday as the annual running of the bulls began in Pamplona, Spain, according to local authorities.
The first "encierro" or bull run on Sunday through Pamplona's old quarter left six people injured, including three who were gored, the Royal Navarre Hospital said in a statement.
The hospital said two of the goring victims were Americans. One was identified as a 23-year-old man from Kentucky and the other as a 46-year-old man from San Francisco. The third victim was identified as a 40-year-old man from La Rioja in northern Spain.
Three others suffered injuries ranging from mild to serious, according to the hospital.
The centuries-old bull run tradition takes place each morning over eight days during San Fermin.
Traditionally, it was used as a way of getting the bulls from the city outskirts to the bull ring.
After launching two rockets, the bulls charge behind amateur daredevils -- many dressed in traditional white attire with dashes of red -- for 825 meters, which is the distance between the corral and the bull ring, according to the festival website.
Injuries are common during the bull run, which has remained a staple of San Fermin despite animal welfare concerns. In 2018, nine people were injured in the first two days.