An off-the-cuff comment by Mexico’s attorney general to cut off a news conference about the apparent killing of 43 missing college students has been taken up by protesters as a rallying cry against Mexico's corruption and drug trade-fuelled violence.

During the session that was televised live Friday, Attorney General Jesus Murillo Karam announced that two suspects had led authorities to trash bags believed to contain the incinerated remains of the slain students, who haven't been seen since being led away by police in the southwestern town of Iguala on Sept. 26.

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This is the site, pictured on Saturday, Nov. 8, 2014, where according to investigators, drug gang members made 43 teachers college students disappear, piling their bodies like cord wood on a pyre that burned for 15 hours. (Alejandrino Gonzalez/Associated Press)

After an hour of speaking, Murillo Karam abruptly signalled for an end to questions by turning away from reporters and saying, "Ya me canse" — a phrase meaning "Enough, I'm tired."

Within hours, the phrase became a hashtag linking messages on Twitter and other social networks. It continued to trend globally Saturday and began to emerge in graffiti, in political cartoons and in video messages posted to YouTube.

'I'm tired of corrupt politicians'

Many turned the phrase on the attorney general: "Enough, I'm tired of Murillo Karam," says one. Another asks: "If you're tired, why don't you resign?"

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Mexico's Attorney General Jesus Murillo Karam says it will be challenging to get the DNA required to confirm the remains are those of the missing students. (Tomas Bravo/Reuters)

Other people used it to vent their frustrations with messages such as "Enough, I'm tired of living in a narco state" or "Enough, I'm tired of corrupt politicians."

Mexicans have reacted with outrage to the disappearance of the students from a rural teachers college and a government response that has failed to fully explain what happened.

Investigators say Iguala Mayor Jose Luis Abarca and his wife, Maria de los Angeles Pineda Villa, ordered police to confront the students, who had gone to Iguala to raise money and had commandeered passenger buses for their use. The couple reportedly feared the students would disrupt an event being led by the wife.

Police handed students to cartel

Iguala police fired on the students in two incidents, killing six people. Officers then allegedly turned over 43 arrested students to the Guerreros Unidos cartel, which is rumoured to have ties to the mayor’s wife.

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The former mayor of the town of Iguala, Jose Luis Abarca, left, and his wife, Maria de los Angeles Pineda, were arrested hiding out in a Mexico City slum last week. The pair have alleged ties to a drug cartel in Guerrero state. (The Associated Press)

At least 74 people have been arrested, including Abarca and his wife, who were found Tuesday hiding in a dilapidated home in a rough section of Mexico City.

Murillo Karam’s press conference Friday included video of alleged cartel members confessing to the killings and telling of their roles in the murders, while another video showed hundreds of charred fragments of bone and teeth that had been dumped in and along the San Juan River in the neighbouring town of Cocula.

The taped confessions included graphic details of cartel members piling the students’ bodies like cord wood on a pyre that burned for 15 hours and then wading into the ashes to pulverize, bag and dispose of remaining teeth and bones.

DNA testing difficult

The attorney general said the state of the remains will make it hard to say definitely whether they are the students.

"The high level of degradation caused by the fire in the remains make it very difficult to extract the DNA that will allow an identification," Murillo Karam said.

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Relatives holding posters with images of the missing students march in protest in Guerrero. (Marco Ugarte/ Associated Press)

He said authorities were putting their last hope with a specialized laboratory in Austria. It is not known how long the process could take.

Manuel Martinez, a spokesman for the families, said the "YaMeCanse" rallying cry was proof that their demand for answers is gaining strength.

"The people are angered and I hope that they continue support us," he said Saturday.

'Vanished' Mexicans

Filmmaker Natalia Beristain was among hundreds of people posting YouTube videos tagged #YaMeCanse.

"Senor Murillo Karam, I, too, am tired," she said. "I'm tired of vanished Mexicans, of the killing of women, of the dead, of the decapitated, of the bodies hanging from bridges, of broken families, of mothers without children, of children without fathers."

"I am tired of the political class that has kidnapped my country, and of the class that corrupts, that lies, that kills," she added. "I, too, am tired."