Marta was at her boyfriend’s house, moulding dough into circles to make tortillas, when five soldiers barged in. They forced the 19-year-old into the bedroom and raped her at gunpoint. Not long after that October afternoon in 1981, Marta fled her hometown of El Mozote in eastern El Salvador.

“The fear that they would come back and do what they did again always stayed with me,” says Marta. “Because that’s what they always did with the young women.”

The small Central American nation was in the early stages of a 12-year civil war that would claim 75,000 lives before it ended in 1992. Most were killed by the US-backed Salvadoran military.

Women from rural communities near guerrilla strongholds were particularly vulnerable to sexual violence at the hands of Salvadoran soldiers, a fact long spoken in whispers but only just now being publicly denounced.

Marta left in the hope she would soon be able to return to her family, when the tension between the military and local community calmed down.

But it never happened. That December, nearly all of Marta’s family – her parents, four of sher even siblings, her boyfriend – the father of her first child – and her aunts, uncles and cousins – were murdered in El Mozote.

The brutal massacre was deemed the worst in modern Latin American history. From December 11 to 13, the US-trained Atlacatl Battalion massacred nearly 1,000 people in El Mozote – 533 children, 220 men and 200 women – trapping them in the local church and houses to shoot them en masse. The military still maintains the official version of events – that the massacre was a confrontation with guerrillas.

“You’re always waiting to see your family, but they aren’t there,” says Marta.

She has lived in El Mozote since returning in 2010 to publicly share the story of the murders as part of a group of survivors fighting for justice for the massacre.

A trial against 18 military officers is now underway.

But it wasn’t until last year that Marta recounted the details of her attack in court. Her testimony – and that of another woman, Fatima – has brought to light new facts about the brutality inflicted upon the residents of El Mozote, particularly women, by the military.

Trying the perpetrators in the El Mozote case would signal a strike against impunity for gender violence in El Salvador as the country continues to grapple with its past – and as women continue to face high levels of domestic and sexual violence.

“The notion of impunity, that I can do it and nothing will happen, exists on a continuum in El – I did it before the war, I did it during the war when I sent messages to the enemy through the body of women, and still today nothing happens [to perpetrators of sexual violence],” says Salvadoran rights activist Morena Herrera. “That sexual violence in El Mozote is at least recognised would be a step forward.”

A dress found at an exhumation site in the village of El Mozote, El Salvador, in 2017. Photograph: José Cabezas/Reuters

In El Salvador, society has “looked the other way” when it comes to gender violence, not just in the case of El Mozote, but also in terms of current day problems, says Sol Yáñez, a Spanish psychologist and professor at Central American University who has worked with El Mozote survivors for decades. “It’s important to validate the pain and experiences of these women.”

Bullet holes in the walls of crumpled houses in El Mozote bear testimony to the 1981 massacre. A memorial stands in the town centre with the figures of a man, woman, and two children holding hands and inscribed with the names of the dead.

Survivors of El Mozote first came forward in 1990 to present a case against the Atlacatl Battalion soldiers. Nearly four decades later, victims still await justice for this and countless other civil-war era abuses.

An amnesty passed as the war ended made it almost impossible for victims to seek justice. But a 2016 supreme court ruling deemed the law unconstitutional, allowing lawyers representing the victims and survivors to reopen the El Mozote case.

Those currently on trial face multiple charges, including murder, acts of terrorism, theft, illegal detention, and aggravated rape.

Rape and sexual violence are widespread but underreported in global armed conflicts, according to a UN report. Social stigma, safety concerns and trauma are among the many reasons women hesitate to come forward about their experiences.

Yáñez says sexual assault survivors from El Mozote have been “doubly silenced.” In El Salvador, the events of the massacre have been disputed for decades.

It wasn’t until 2012, when the inter-American court of human rights officially recognised the massacre, that the validity of victims’ testimonies became more widely accepted.

Given that many Salvadorans denied it ever happened, women were even more afraid to come forward about sexual violence.

“They think: ‘They aren’t going to believe me. They are going to think that I did something for this to happen, and all the other social stigma that is associated with rape,’” says Yáñez.

A woman places portraits of some of the survivors of the El Mozote massacre in a local park. Photograph: Oscar Rivera/AFP/Getty Images

Since witnesses started to come forward in the 90s, allegations of sexual assault have been frequent. Survivors recount seeing bodies of dead women with their skirts pulled up, and hearing the screams of those who were separated from men and taken to the mountains.

Marta and Fatima are the first two women to speak up about their personal experiences. “Women are finally talking because a window has finally opened for the possibility of justice,” says Herrera.

“I said to myself: ‘Maybe they are finally going to pay,’” says Fatima, who was gang-raped by soldiers who forced her cousin to watch before shooting him dead. She gave testimony in the hope of seeing justice in the case.

Lawyers expect the El Mozote trial to continue for up to a year. Marta remains optimistic about the outcome.

“Before, it wasn’t possible, but now there is going to be justice,” Marta said.

Names have been changed