BUENOS AIRES, Argentina, Sept 27, 2025 (BSS/AFP) - Thousands of protesters took to the streets of Buenos Aires on Saturday to demand justice for three young women whose torture and murders were live-streamed on social media, in a case that has shocked Argentina.

The victims' relatives held a banner with their names -- "Lara, Brenda, Morena" -- and placards with their images, flanked by supporters as they marched to Parliament.

"It was a narco-feminicide!" "Our lives are not disposable!" read signs and banners as protesters banged on drums at the march, organized by a feminist group.

The bodies of Morena Verdi and Brenda del Castillo, cousins aged 20, and 15-year-old Lara Gutierrez were found buried Wednesday in the yard of a house in a southern suburb of Buenos Aires, five days after they went missing.

The crime, which investigators tied to drug gangs, was perpetrated live on Instagram and watched by 45 members of a private account, officials said.

- 'Bloodthirsty' -

"Women must be protected more than ever," Brenda's father, Leonel del Castillo, told reporters at the protest. He had earlier said he had not been able to identify his daughter's body due to the abuse she had endured.

Antonio del Castillo, grandfather of the slain 20-year-old cousins, was in tears, calling the killers "bloodthirsty."

"You wouldn't do what they did to them to an animal," he said.

"I have hope that the truth will be revealed," he added. "I ask people to stand with us."

On Friday, National Security Minister Patricia Bullrich announced the arrest of a fifth suspect, bringing the total to three men and two women.

The fifth suspect, accused of providing logistical support with a car, was arrested in the Bolivian border city of Villazon.

Authorities have released a photograph of the plot's alleged mastermind, a 20-year-old Peruvian, who remains at large.

- 'Injustice' -

Investigators said the victims, thinking they were going to a party, were lured into a van on September 19 allegedly as part of a plan to "punish" them for violating gang code and serving as a warning to others.

Police discovered the video after one of the detainees revealed it under questioning, according to Javier Alonso, security minister for Buenos Aires province.

In the footage, a gang leader is heard saying: "This is what happens to those who steal drugs from me."

Argentine media reported the torturers cut off fingers, pulled out nails, beat and suffocated the victims.

Meta, the parent company of Instagram, disputed that the livestream occurred on its platform.

"We have not found any evidence of the livestream taking place on Instagram. Our team continues to cooperate with law enforcement as they investigate this horrific crime," a spokesperson told AFP.

Federico Celebon, a cousin of Brenda and Morena, told AFP the young women had sometimes engaged in sex work "to survive," without their families' knowledge.

They had "bad luck" to "find themselves at the wrong time with the wrong people," he said.

According to several media outlets, the women had been asked to attend the party as prostitutes.

Yamila Alegre, a 35-year-old leatherworker at the march on Saturday, blasted media coverage of the case.

"We always try to make the girls feel guilty, we know everything about their lives, what they were doing there, what their family is like... we publish their photos but we know nothing about the perpetrators, not their names, their faces are blurred," she said.

Del Valle Galvan, Lara's aunt, denied that the 15-year-old was involved with drugs or prostitution.

"There is poverty in our neighborhood, but what people say about Lara is false," she said.

"We want justice to be done, for nothing to be covered up, for the whole truth to come out so that those responsible can be held accountable for their actions. We are not afraid!" she told AFP.