Two soldiers and three federal police officers have been ordered to stand trial for torture following the publication of a video in which three of them are seen partially suffocating a woman with a plastic bag.

The filmed interrogation took place in February 2015 in the small town of Ajuchitlán that is located in a particularly drug-war ravaged part of the beleaguered southern state of Guerrero. The civilian courts, however, did not get involved until after a film of it was posted on YouTube earlier this month and caused a furor.

The video shows the two soldiers and one police officer pressuring the woman to answer questions with the help of the plastic bag. It also shows them putting a gun to her head. The woman was later named as 24-year-old Elvira Santibañez, an alleged member of La Familia Michoacana drug cartel.

The images have fueled long-standing allegations that Mexican security forces systematically use torture, particularly in the context of their military-led efforts to crackdown on organized criminal groups.

President Enrique Peña Nieto's government has vigorously rejected numerous critical reports by national and international human rights groups.

His government appeared particularly unhappy about a 2015 report by the UN rapporteur for torture Juan Méndez that described the practice as "generalized" and noted that it goes almost completely unpunished. "This conclusion does not correspond to reality," the foreign ministry said in a curt statement.

Last month's global human rights report from the US State Department was greeted with silence. "The most significant human rights-related problems included law enforcement and military involvement in serious abuses, such as unlawful killings, torture, and disappearances," the report said.

This month's video, however, spurred Defense Minister General Salvador Cienfuegos to call a special gathering of 26,000 troops at the main military base in the capital, and offer an unprecedented apology.

"I have brought you here today because it is necessary to publicly show our indignation over these regrettable events," he said. "I offer a heartfelt apology to all of society for this inadmissible event."

Screenshot via YouTube.

The two Mexican soldiers involved in the case were already arrested in January in relation to the interrogation nearly a year before. They were, however, only charged within military courts for disobedience. The female federal police officer featured in the film — that has now been taken down from YouTube — was arrested soon after its publication. The authorities have not provided details of the alleged role of the two other federal officers currently facing trial.

Torture is a particularly delicate issue at the moment in Mexico because of renewed attention to the Ayotzinapa case in which 43 student teachers were disappeared after being attacked by police in September 2014.

A group of international experts convened by the Inter-American Commission on Human Rights released their final report last weekend in which they highlighted the way the government's investigation into the atrocity has relied on confessions made by detainees who have since made credible allegations of torture.