More than 250 skulls have been found over the last several months in what appears to be a drug cartel mass burial ground on the outskirts of the city of Veracruz, Mexican prosecutors said on Tuesday.
Veracruz state's top prosecutor, Jorge Winckler, said that the clandestine pits appeared to contain remains of cartel victims killed years ago.
The news came as no surprise to Lucia Diaz, one of the mothers of people who have disappeared whose group is known as Colectivo Solecito.
The mothers pushed authorities to investigate the fields where the skulls were found because they suspected more than a year ago that the wooded area known as Colinas de Santa Fe was a secret burial ground.
In the face of official inaction, the activists themselves went to the fields starting in August 2016, sinking rods into the ground to detect the telltale odor of decomposition, and then digging.
When they find what they believe are burial pits, they alert authorities, who carry out the final excavations.
So far, Diaz said, searchers have found about 125 pits that contain about 253 bodies. Nobody knows when the burials began, but Diaz said some were quite recent.
Some of the bodies had a lot of connective tissue. You could see an ear, or recognise part of a face - Lucia Diaz, Colectivo Solecito
First official recognition
Winckler, in the first official recognition, seemed to say the burials occurred before the new state administration took office in December.
"For many years, the drug cartels disappeared people and the authorities were complacent," Winckler said in apparent reference to the administration of fugitive former governor Javier Duarte and his predecessors.
Duarte resigned as governor two months before his term ended last year and disappeared. He faces charges that include money laundering and organised crime and officials have accused him thoroughly looting state coffers.
Winckler said that resources needed for DNA tests in criminal investigation had vanished, leaving officials to depend on help from the federal government and groups such as the Red Cross.
Winckler said that the state has reports of about 2,400 people who are still missing and "Veracruz is an enormous mass grave."
More than 250 bodies were discovered in April 2011 in burial pits in the town of San Fernando, in Tamaulipas state, close to the US border.
Drug gangs in some places in Mexico have taken to burning or dissolving their victims' bodies in corrosive substances in order to avoid discovery.