City prosecutor Rodolfo Rios said at least seven bodies had been exhumed by midday Thursday from the grave east of Mexico City's downtown and investigators were searching for more remains, the Los Angeles Times reported.
Twelve men and women, ages 16 to 34, disappeared May 26 from the Heaven bar in the Zona Rosa district, just a block from Reforma Boulevard, the city's main roadway, and not far from the U.S. Embassy.
Authorities said they suspected the group was snatched as part of a battle among small-time drug dealers. Families have maintained the missing weren't involved in drugs, but all were from the Tepito neighborhood, which is known for counterfeiting and other criminal activities, the Times said.
Speaking at a news conference, Rios said it would take at least 48 hours to identify the decomposed bodies.
Six people, including the bar's owners, have been arrested.
A lawyer representing families of five of the missing told CNN-Mexico he got a call about the location where the bodies could be found.
Attorney Ricardo Martinez said his source told him there were 13 bodies at the site, possibly in two mass graves.
Rios said Thursday one grave so far was being investigated.
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