TENS of thousands of people have protested on the streets of Spain after a group of men accused of gang-raping an 18-year-old were acquitted.

The five men — José Ángel Prenda, Antonio Manuel Guerrero, Ángel Boza, Alfonso Jesús Cabezuelo and Jesús Escudero, all from the southern city of Seville — were acquitted of raping the woman, who has not been identified, instead being found guilty for the lesser offence of sexual abuse and sentenced to nine years in prison.

The victim said she was confronted by a group of five men in their mid-20s as she was walking to her car during the famous Running of the Bulls festival in Pamplona in 2016.

She said they offered to accompany her to her vehicle, but instead pinned her up against a wall, told her to “shut up” and took turns sexually assaulting her.

The woman was later found curled up in a foetal position, crying on a bench.

The Navarre court heard the men filmed the incident with their smartphones and posted the footage on a WhatsApp messaging group, bragging that “us five are f***ing one girl,” “there is more than what I’m telling you,” and “there is video”. They referred to themselves as “La Manada”, or “Wolf Pack” in English.

The “Wolf Pack” case — as it has come to be known — has been a central part of Spain’s media, largely based on the tactics used to prove the woman was not a victim of rape.

According to the court, the woman was seen to be in a “passive, submissive stance” with her eyes closed, which the men’s attorneys used as evidence of consent.

It included a special report containing the woman’s social media posts.

They pointed to an Instagram post of a T-shirt with the words, “Hagas lo que hagas, quítate las bragas” (“Whatever you do, make sure you take off your underwear”) which is a reference to the Spanish version of reality TV show Jersey Shore. The men’s attorneys argued that this counted as evidence that the woman was willing to engage in sexual acts consensually.

A private investigator was also hired to secretly tail the woman in the days after the incident. He took photos of her smiling and laughing with friends, which was later given as evidence that the woman had not been traumatised by the incident.

Prosecutor Elena Sarasate said she was clearly terrified during and after the ordeal.

“The defendants want us to believe that on that night they met an 18-year-old girl, living a normal life, who, after 20 minutes of conversation with people she didn’t know, agreed to group sex involving every type of penetration, sometimes simultaneously, without using a condom,” she said, according to The Guardian.

She questioned how the sex could have been construed as consensual when the group had stolen her phone.

“The obvious thing would be to exchange phone numbers, not steal her phone.”

The men were found guilty of “sexual abuse” — a lesser charge in Spanish law than sexual assault — which excludes violence and intimidation. They were sentenced to nine years in prison, while the prosecution had sought 22 years.

The decision sparked large-scale protests throughout the country, including in Madrid, Barcelona, Valencia, Pamplona and Alicante.

Crowds protested outside the courthouse, with people shouting: “It’s not sexual abuse, it’s rape!”

Several authority figures were vocal in condemning the judge’s decision.

“I am outraged that after a gang rape you must suffer the violence of patriarchal justice,” Barcelona mayor Ada Colau said in a Twitter message addressed to the victim.

“You are not alone, today we will be thousands taking to the streets and joining our voices to yours,” she added.

The hashtags #TeSeCreo (I Believe Her) and #YoSiTeCreo (I Do Believe You) began trending across the country following the verdict.

Spain’s Deputy Prime Minister Soraya Saenz de Santamaria said that while the judge’s sentences must be respected, the authorities need to analyse what had happened “to avoid such behaviour happening again in this country”.

The judge said there was no evidence of violence or intimidation in their actions.

Both sides intend to appeal the verdict.