A half-tonne bull skewered two Britons and an American during the third bull run of the San Fermin festival in the Spanish city of Pamplona on Monday.
The black bull called Fugado (Escapee) charged into a crowd of runners with its horns lowered but no one was seriously hurt.
The ABC reports another four people were injured as the bulls covered the 850metre course in three minutes and 37 seconds.
Last year 20,500 people took part in the festival's eight bull runs.
Officials expect about half a million people will flock to the city of 200,000 during the festival, which dates back to medieval times.