A total of 13 skeletons have been found at a hidden grave discovered this week in the central Mexican town of Tlalmanalco, according to federal prosecutors, who said five of them correspond to members of a group of 12 youths who went missing from a Mexico City bar in May.

The Mexico Attorney General's Office said Friday it had fully identified Alan Omar Atiencia Barranco through DNA testing, while four other youths who disappeared from the Heaven bar in an upscale area of Mexico City on May 26 have been identified by other means, including tattoos.

The announcement by the federal AG's office came 48 hours after the grave - covered with cement, asbestos and lime - was discovered Wednesday on the La Mesa ranch in Tlalmanalco as part of a weapons investigation.

Mothers of the victims, however, demanded to see the bodies so they could confirm the identities themselves, no matter the condition of the remains.

"I can't be sure if it's him until I've seen the body. I want to see the body first because I haven't seen it. Even if it's in decomposition, I don't care. I want to really be sure that it's my son," Maria Victoria Barranco, Alan Omar's mother, said after meeting with prosecutors.

Although forensics personnel were still working to identify the other eight bodies, Ricardo Martinez, an attorney representing the families of five of the missing youths, told Efe Friday his sources informed him there was a 99 percent chance the remains corresponded to the young people.

Referring to the discrepancy between the number of bodies found in the grave and the number of youths who went missing from the bar, he said the additional corpse could correspond to some unreported kidnapping case that occurred that same May 26 or to Antonio Cesar Ortega, a youth who disappeared from the same bar in 2011.

Two residents of Tlalmanalco, which lies about 20 kilometers (12 miles) southeast of Mexico City, have been arrested, Mexico City District Attorney Rodolfo Rios said Thursday.

The burned body of a suspect in the mass abduction was discovered last month in Morelos state, south of Mexico City.

Dax Rodriguez Ledezma, one of the owners of the Heaven bar, "was the subject of an order to locate and appear issued by ... the capital's special prosecutor's office for kidnappings as the person likely responsible" for the abductions, the Mexico City government said last month in announcing the discovery of his body on June 22.

Martinez, for his part, said the case should be taken up by the federal AG's office instead of Mexico City prosecutors because an organized crime gang was behind the killings.

"How is it possible that no one realized we have organized crime in the Federal District (Mexico City)?" he asked rhetorically.

What is worse, he said, is that "they want to keep covering this up" by arguing the crime was linked to a turf battle among small-time drug dealers. 

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