Mass grave outside Mexico City August 24, 2013 Police guard the entrance to Rancho La Mesa where a mass grave was found. MEXICO CITY: A mass grave has been found near Mexico City and authorities are investigating whether the victims are a group of young people kidnapped en masse from a bar in May, a crime that shocked and perplexed a capital city not accustomed to such brazen violence. Chief prosecutor Rodolfo Rios Garza said it would take at least two days to analyse evidence and identify the bodies found in the town of Tlalmanalco. At least seven have been excavated, but officials said there could be more. The 12 young people were abducted from the Heaven bar in a popular nightclub district steps away from Paseo de la Reforma, a main thoroughfare. It was the kind of kidnapping that occurs more often in areas of the country in the throes of the drug war but less so in the capital. Security video showed the people getting into cars and being driven away. They were never seen again. Mexican media have focused on the group's connection to the city's Tepito neighbourhood, a slum synonymous with crime and contraband. Reports said some of the abducted had connections to drug dealers, although their families said they were not criminals. Relatives have held protests to complain about the investigation's slow progress. A spokesman for the city's prosecutor's office said five suspects were in custody. Ricardo Martinez Chavez, a lawyer for the families of some of those abducted, said one suspect had led the authorities to the mass grave. Mexico's Attorney-General Jesus Murillo Karam said the authorities found the mass grave during an investigation into a tip about arms trafficking in the area. Mr Rios Garza did not disclose any information about the bodies found on Wednesday. Another mass grave, which contained five bodies, was found in the same area in 2011. The case challenged the conventional wisdom that this sprawling capital has remained relatively untainted by the kinds of vicious violence sweeping much of the rest of the country. New York Times, Los Angeles Times