It began as a call to arms to women in Spain after last week’s incendiary acquittal of five men on rape charges in Pamplona.



“We must tell of the aggressions, the violations, compañeras,” the journalist Cristina Fallarás tweeted, urging her followers to speak out over sexual violence using the hashtag #Cuéntalo.

But across the Atlantic the message was also received loud and clear, with hundreds of thousands of Latin American women seizing on the Twitter campaign to denounce the rampant gender violence blighting their region and their lives. Each day 12 Latin American women are victims of femicide, according to the UN’s Economic Commission for Latin America and the Caribbean.

From Buenos Aires to Bogotá, often horrific accounts of abuse rained in as word of the hashtag – which roughly translates as “tell your story” – spread. Argentina’s Clarín newspaper said more than 430,000 tweets featuring #Cuéntalo were posted in one day alone.



“#Cuentalo is tearing my soul into a thousand pieces ... Each story tells me we must carry on fighting for women,” tweeted Paula Andrea, a Colombian model.



Some chose to use the Spanish-language initiative to recount their own experiences.



“One night my ex-husband wanted to have sex when I didn’t. To avoid being raped, I locked myself out on the balcony and spent the whole night there without my kids noticing,” tweeted Ana Alonso Ferrer from Cuenca, Ecuador’s third largest city.



Many, though, chose to tell the stories of women who had been robbed of their voices – friends, relatives or strangers lost to a seemingly unstoppable wave of deadly violence against Latin American women.



“My husband shot me in the head, wrapped up my body and threw it in the Potrerillos Dam,” tweeted a woman in Argentina, channeling the voice of one recent murder victim there. “I’m the one telling you because Concepción Arregui cannot.”



Karla Hernández, a politician in El Salvador who has campaigned against femicide, used the hashtag to highlight the case of a female police officer thought to have been shot and disappeared by fellow officers last December. “My family are still waiting. They don’t know if I’m dead or alive,” Hernandez wrote, adding: “I’m telling you because Carla Ayala can’t.”



In a 271-character post Ana Lara Vargas, a human rights lawyer and activist from the Mexican state of Hidalgo, remembered Jessica González Mandujano, a 31-year-old mother of three who she said had been killed by her abusive husband in 2014. “I’m telling the story since Jessica is gone,” she wrote.

Facebook Twitter Pinterest Protesters in São Paulo after the gang rape of a 16-year-old girl in 2016. Photograph: Xinhua/Barcroft Images

Vargas, part of the Colectiva de Mujeres Contra La Violencia group, said she believed #Cuéntalo could help revive the experiences of forgotten Latin American women. “This hashtag is a really important way of telling these stories ... The campaign is a chance to give voice to those women who have neither access to justice nor the means to share their stories,” she said.



The urgency of the campaign in Latin America was underscored by a violent attack on a young Chilean woman by five men on Sunday that has been compared to the attack in Spain which inspired #Cuéntalo.

Erika Guevara-Rosas, Amnesty International’s Americas director, said she was not surprised the initiative – which follows 2016’s #NiUnaMenos (“not one less”) movement – had struck a chord in a region with such high rates of violence against women.



“Latin America and the Caribbean remains one of the most violent regions with regards to girls and women’s rights in general. Fourteen of the 25 countries with the highest rates of femicide are here in the region including countries such as Mexico, which tops the list, Central American countries like Nicaragua, Guatemala, El Salvador and Honduras, and Argentina and Brazil. It is something that is endemic,” she said.



But femicide was only “the most radical expression of discrimination and violence against women” in a region notorious for machismo, Guevara-Rosas added. It is also home to six of the eight countries with blanket bans on abortion, for example. Faced with staggering violence and almost total impunity, society was finding its voice: “Online and offline, people are mobilising,” she said.

Vargas, the Mexican activist, said she hoped #Cuéntalo would both highlight widespread violence and boost her campaign to secure justice for Mandujano, one of 19 cases of femicide in Hidalgo in 2014.



Vargas recalled how in July that year, after years of savage beatings, Mandujano fled her husband after reporting him to authorities. But on 14 August 2014 he tracked her down to a safe house in the city of Pachuca and shot both her and her brother dead.



“Four years have passed and they haven’t detained him,” Vargas complained. “The feminicida is still at large.”



