Dozens of animal rights activists dressed as dinosaurs have been chased by fellow demonstrators through the streets of the Spanish city of Pamplona to protest against alleged cruelty at the San Fermin Running of the Bulls festival.

During the protest, the dinosaurs were supposed to represent bulls, with the chasing mob symbolising the San Fermín revellers.

Activists carried placards reading: “Bullfighting is Prehistoric.”

They said the point was to show that runs could be light-hearted, and held without any cruelty to animals.

The action marks the 18th annual protest led by People for the Ethical Treatment of Animals (Peta), and the Spanish NGO AnimalNaturalis.

The protests are normally held a day before the festival gets under way with the traditional “chupinazo” firework blast at midday in Pamplona’s town hall square. The runs begin on Thursday.

Chelsea Monroe, Peta senior digital campaign officer said: “Bullfighting is the long ritualised execution of bulls and many tourists who come to the bull runs don’t actually realise that the same bulls they’re running down a couple of streets with are later killed in the bullring that day.

“They’re stabbed over and over again for 20 minutes until they’re dead.

“We want the tourists to know that their money is supporting this really cruel industry.”

The protests do little to dampen enthusiasm for San Fermín, which normally sees Pamplona’s population of 200,000 balloon to some one million during peak times of the nine-day festival.

The festival was suspended for the past two years because of the coronavirus pandemic. Authorities fear crowd activities at the festival may lead to a major increase in infections this year as well.

The festival highlight is the early morning “encierro”, or run, which sees thousands of people running like mad to avoid six bulls as they charge along a winding, cobblestoned route to the city’s bullring.

The rest of each day is for eating, drinking, dancing, and cultural entertainment.

The six bulls are invariably killed in bullfights each afternoon during the festival.

“The debate over the future of bullfighting in Spain has never been so alive and the authorities must take a clear stance,” said Jana Uritz of AnimalNaturalis in a statement.

“We demand the necessary courage from them to say whether they favour animal torture or, on the contrary, are ready to prohibit such barbarities.”

Bullfighting is still immensely popular in Spain although the movement against it has gained momentum in recent years.

The sport is banned only in the Canary Islands although it is not practiced much, or at all, in some other regions such as Catalonia and the Balearic Islands that include Mallorca, Menorca and Ibiza.

The animal rights groups cite culture ministry figures, saying 90% of Spaniards did not attend any festival event involving bulls in 2014-2015, the last year the issue was surveyed.