The spectacular annual running of the bulls in the northern Spanish city of Pamplona has been officially opened with a rocket fired from the town hall.
Thousands of visitors descend on Pamplona
"Pamplonians. Long Live San Fermin!" town councillor Juan Luis Sanchez de Muniain shouted from the building's balcony.
Firecrackers snapped and revellers doused each other with champagne as the nine-day bull-running festival in honour of San Fermin - the son of a Roman Senator that ruled Pamplona in the third century - began in earnest.
The town's main square was a sea of red scarves and white trousers - the traditional colours worn by people - mostly young men - who will run against the bulls in the controversial event.
Six bulls are released from a pen into a closed off street each morning starting on 7 July.
They stampede 825 metres (902-yards) from the
corral to the bullring where they will face matadors later in the day.
In front of them run hundreds of people hoping to keep clear of the animals' hooves and horns.
It looks dangerous, and it is.
Runners risk being trampled on by other participants as well as being gored or flung aside by the bulls and injuries are common.
Since records began in 1924, 13 people have been killed, the last victim being a 22-year-old American who was gored to death in 1995.
Touch wood, there will be no deaths this year
Yolanda Barcina, mayor of Pamplona
However, Pamplona's mayor, Yolanda Barcina, has said many sports are more dangerous.
"There are injuries, but it has been a long time since there have been any deaths.
"I'm touching wood for this to continue," she said.
The festival - which has been held since 1591 - was made internationally popular by Ernest Hemingway's 1926 novel "The Sun Also Rises."
The first run this year is scheduled for Monday morning at 0800 (0600 GMT), and until then the visitors will throng the streets and cram the bars either to work up their courage or to take in one of Europe's raunchiest 24-hour parties.
Not everyone is happy, however.
Animal rights activists, including some from the organisation PETA (People for the Ethical Treatment of Animals) stripped naked in the town on Saturday to protest at both bull running and bull fighting.
Campaigners wanted to highlight concerns for the bulls
The demonstrators were hoping to run naked down the bull run.
Most were prevented by police, but some breached security lines to complete the course, flanked by hundreds of clothed demonstrators along the way.