Mexican authorities are investigating whether human remains found in a park outside the capital belong to 12 young people whose kidnapping in May shocked the city, officials said Thursday.
Mexico City's top prosecutor, Rodolfo Rios, said the remains of seven people have been recovered since the search began Wednesday and that investigators were looking for more bodies in the rough terrain.
The mass grave was discovered in a park in the town of Tlalmanalco, some 30 kilometers (19 miles) southeast of the capital, and police put up a checkpoint on a dirt road surrounded by corn fields one kilometer from the site.
"For the moment, seven bodies were recovered from the site, and obviously due to the state of decomposition we will have to wait for an autopsy," Rios said.
Rios told Foros Television it would take at least two days to get results from DNA tests to identify the remains. An official from the federal attorney general's office said five of the remains were mere bones.
The 12 victims were kidnapped from a Mexico City bar in broad daylight last May in a case that raised concerns about security in the capital, which has been relatively immune from the country's drug cartel violence.
Rios has linked the mass kidnapping to a dispute between two gangs known as La Union and Tepis, which sell drugs in the city's rough Tepito neighborhood. But Mexico City authorities insist that the bigger cartels do not operate in the capital.
Most of the abductees hail from Tepito and two of them, including 16-year-old Jerzy Ortiz, are sons of jailed criminals.
The group was whisked away by 17 men who walked into the Heaven bar on May 26 and took them away in several cars, just blocks away from the federal police headquarters and the US embassy, according to footage from security cameras.
Two bar owners have been arrested in connection with the case. The charred remains of a third associate was found in the central state of Morelos last month.
Jerzy's aunt, Eugenia Ponce Ramos, told AFP that Rios spoke with the families and told them that authorities have yet to confirm the identities of the bodies.
"We have to stay calm," said Ponce, who is among scores of family members who have held protests in the capital to demand answers about the fate of their loved ones.
Mexico City authorities initially classified the disappearances as a missing persons case before determining it was a mass kidnapping.
Officials have since offered a reward of more than $750,000 for information that could help the investigation.
Heaven is an after-hours bar that was briefly closed in 2011 after a man vanished.
But Mexico City Mayor Miguel Angel Mancera insists that the mass kidnapping is an "isolated" case linked to local gangs.
The former Mexico City police chief, Manuel Mondragon y Kalb, who now heads the federal police, told Mexican television last month that the country's main gangs have "crystalized" in some areas of the capital.