Claudia Medina Tamariz was asleep in her home in the Gulf coast port of Veracruz with her husband when Mexican marines burst in and arrested them both in August 2012.

Blindfolded and handcuffed, Medina believes she was taken to a local navy base where her captors accused her of working with organized crime. Over a period of hours, she says, she was beaten, sexually assaulted, jolted with electric shocks and subjected to simulated drowning — two independent medical examinations found evidence consistent with her version. She was forced to bathe in front of her captors.

Eventually Medina and others were paraded in front of television cameras along with weapons and drugs and slapped with a raft of organized crime charges. Later she discovered that the statement she gave, but was not shown before signing, had been altered into a confession in which the marines said they arrested Medina and her husband when they were caught driving a vehicle with weapons and drugs.

"The authorities when they exhibit you do it with the purpose of keeping you quiet as a woman," Medina said Monday. "They know how to injure you as a woman."

The human rights group Amnesty International says Medina's experience is common among women arrested in Mexico. In a report released early Tuesday, the group said that in interviews with 100 incarcerated Mexican women, 72 reported sexual torture during their arrests. Ninety-seven had been beaten or received some kind of physical abuse. All 100 reported at least harassment or psychological abuse.

"What we see is that women are often targeted because of their gender, their bodies are often used in a certain way and targeted in a certain way, and we often see women from disadvantaged backgrounds are the ones that are the easiest targets for authorities," said Madeleine Penman, a researcher with Amnesty International.

Amnesty International showed the report to the government Monday, but the Attorney General's Office did not respond to a request for comment from The Associated Press before the paper was released.

Penman said Amnesty International decided to focus a report on female survivors of sexual torture because it had not received much attention. She said researchers would have liked to interview even more women, but Mexican authorities placed obstacles in their way.

Much of the abuse has been tied to Mexico's war against drug cartels, with women often being swept up when authorities arrest men or are simply looking to show results to the public, the report said.

It said the sexual nature of the torture and the stigma makes it less likely women will speak out.

Medina, a mother of three children who had worked selling natural products, is free and isn't one of the 100 women interviewed for the report. But she and the group said her experience mirrored those collected in the report.

When the marines turned Medina over to federal investigators, she initially did not tell about the torture. "I was scared, because they had threatened that if I talked about what had happened during those 36 hours they would find my children," she said.

But the day after she was taken to a women's prison Medina told a judge that she had been tortured. Three days later the judge threw out the most serious organized crime charge.

After 23 days in prison, Medina was able to get bond and fight her case. All but one of the charges — weapons possession — were tossed out. She filed a complaint with Mexico's National Human Rights Commission about her treatment and began speaking out, but to date the body has had not published a recommendation in the case.

A year and a half after her arrest, prosecutors issued a new arrest warrant for Medina listing all the old charges. She saw it as a clear threat and message to stay silent. After another year of challenges, a judge exonerated Medina of all charges.

Her husband remains imprisoned awaiting a judge's ruling on his charges.

"I consider it already routine for military authorities," Medina said of the use of torture and other abuse. "I have always said I feel like (torture) is like a cancer that is growing and growing and growing."

Amnesty International's report points out that Mexican lawmakers are debating new torture legislation and the Attorney General's Office has created a special unit to investigate torture. But of thousands of complaints of torture since 1991, only 15 have resulted in federal criminal convictions.