A red-and-white sea of revellers soaked each other with wine in a packed Pamplona square to kick off Spain's most famous fiesta, the San Fermin bull-running festival.
A shout from the City Hall balcony of "Viva San Fermin!" and the lighting of a firecracker known as the "chupinazo" on Sunday set off the bedlam, which marks the official start of the nine-day street party.
Masses of fun-seekers from around the world squeezed into the square under an overcast sky cheered, danced and sprayed each other with sangria and cheap wine, turning white shirts to pink.
The crowds dressed in traditional white outfits and red neck scarves passed large yellow and white inflatable balls over their heads as scores looked down from crowded apartment balconies.
Sam Madden, a 26-year-old electrician, came from London with a friend to take part in a bull run.
"We don't know what to expect, if we are going to die or what. It's cool, it's going to be crazy. We know it can be dangerous but we have to do it for a bit of adrenaline," he said.
The festival in honour of Saint Fermin, the first bishop of Pamplona, dates back to medieval times and it features religious processions, folk dancing, concerts and round-the-clock drinking.
But the highlight is a bracing, daily test of courage against a thundering pack of half-tonne fighting bulls through the city's cobbled streets.
Each day at 8am hundreds of people race with six huge bulls, charging along a winding, 848.6-metre course through the narrow streets to the city's bull ring.
The first bull run, which traditionally draws the largest number of participants, is on Monday. A run takes on average just under four minutes.
Source: AAP
