Seven people have been gored by bulls during the sixth day of this year's annual bull-running festival in the northern Spanish town of Pamplona.
The San Fermin festival began in the 16th Century
Local authorities said three people were in a serious condition and had undergone operations in hospital.
Several others were trampled in incidents at the San Fermin festival, in which thousands of revellers try to dodge bulls let loose in the streets.
At least 13 people have been killed since record-keeping began in 1924.
The most serious casualties of Thursday's bull-run, or "encierro", included a 23-year-old Mexican and a 26-year-old German.
It was the bloodiest day since the week-long festival began on Friday.
Each morning at 0800 (0600 GMT), up to six bulls and a number of steers are released from a pen into a closed-off street.
They are then run the 825m (2700ft) to the bullring, where they will face matadors later in the day.
The festival, which has been held since 1591, was made internationally popular by Ernest Hemingway's 1926 novel, The Sun Also Rises.
It has been the target of protests by animal rights protesters, who say bull-running is cruel.