March 14 (UPI) -- Mexican authorities are investigating the macabre discovery of a large number of human skulls in the gulf coast state of Veracruz, at a location that one official called "an enormous mass grave."
At least 250 human heads were found at the site, which police suspect had been used for years as a dumping ground for corpses by drug cartels.
"In my view, once we have opened all the mass graves in the state, it could become the biggest mass grave in Mexico, or even the world," state prosecutor Jorge Winckler told Televisa.
"For many years, organized crime disappeared people with the connivance of the authorities and they went and dumped them in mass graves created for that purpose."
Winckler said more human remains could be found before the investigation ends. Televisa reported that only about 30 percent of the grave site has been searched so far.
Veracruz, about 200 miles due east of Mexico City, has long been a stronghold for the Zetas cartel. Last month, 11 people were found dead in the Veracruz state city of Boca del Rio in one drug-related case, and 35 bodies were found in 2011 in another.
Many of the skulls have been identified as persons who were previously reported missing, Winckler said.
The prosecutor heaped some of the blame on former Veracruz governor Javier Duarte, saying his administration neglected missing persons cases during its 2010-2016 tenure. Duarte, 43, was forced out of office in October due to federal corruption charges and has been on the run for five months. Authorities are offering a 15-million peso reward ($761,000) for information leading to his capture.