Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

MEXICO CITY — Mexico's defense secretary formally apologized to the country Saturday for a video-recorded incident of torture involving two soldiers and a federal police officer.

Gen. Salvador Cienfuegos Zepeda addressed a sea of green-uniformed soldiers in a televised address that illustrated just how damaging the graphic torture video has been for the institution.

"In the name of all who make up this great institution, I offer a sincere apology to all of society offended by this unacceptable event," Cienfuegos said. He urged soldiers and citizens to come forward to report other abuses.

Mexico's Defense Secretary Gen. Salvador Cienfuegos Zepeda addresses soldiers at the Number 1 military camp in Mexico City, Saturday, April 16, 2016. Marco Ugarte / AP

Torture by police and armed forces has long been criticized as a far too common technique for extracting information or confessions from suspects.

But the video of a young woman having a rifle muzzle pressed to her head by a female military police officer and having a plastic bag placed over her head by a female federal police officer has stirred outrage. The incident occurred Feb. 5, 2015, in Ajuchitlan del Progreso in the southern state of Guerrero. The state has seen a massive deployment of soldiers and federal police to battle the drug cartels.

Cienfuegos said such acts "not only denigrate us as soldiers but also betray the confidence that this institution has earned day by day."

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

"Let it be clear: We must not, nor can we confront illegality with more illegality," he said.

In the past, the military has assumed a much more defensive position when confronting allegations of abuse. The widely circulated video made that impossible.

"Unfortunately they only give these apologies when they have no choice, when there is no alternative because the images are irrefutably captured in a video," said Jose Miguel Vivanco, Americas director at Human Rights Watch. The usual reaction is to deny and even cover up incidents, he said. "The lesson that these soldiers and officers take away is not to take photographs much less leave evidence like a video."

Since former President Felipe Calderon stepped up the country's battle with drug cartels in December 2006, the military has assumed a more active role in internal security and that has continued under his successor, President Enrique Pena Nieto. In some areas soldiers took over policing duties as corrupt local police forces were disarmed and disbanded.

International and domestic human rights organizations have been highly critical of this role and the abuses they say it brought.

In February, Mexico's Navy announced that it was investigating several marines for allegedly torturing and sexually abusing six female suspects in the Gulf coast state of Veracruz in 2012. Mexico National Human Rights Commission had recommended the investigation.

In October 2015, it was announced that the United Nations Committee Against Torture found Mexican soldiers had tortured four men with beatings, asphyxiation and electric shocks in the northern state of Baja California in 2009.

That same month, U.N. High Commissioner for Human Rights, Zeid Ra'ad Al Hussein, recommended that the government set "a time frame for the withdrawal of the military from public security functions."

In December 2014, the U.N.'s Special Rapporteur on Torture published a report that concluded that "torture is generalized in Mexico. It occurs especially from the moment when a person is detained until he or she is brought before a judge, and is used as punishment and as a means of investigation."

On Thursday, two federal security officials told The Associated Press that the suspect in the video has been in prison for more than a year on weapons charges. One of the sources, who both requested anonymity because they weren't authorized to speak about the case, said the federal police officer in the video had been identified and was being held at a federal police installation. She had not been charged.

The two soldiers are being held in a military prison and Cienfuegos said Saturday that in addition to military justice, they will be investigated by federal prosecutors for crimes against a civilian.

The attorney general's office said Thursday it had opened a torture investigation.