Investigators have been combing through this site full of skeletal remains.
CNN  — 

Mexican investigators used drones and ground-penetrating radar to search an area in the coastal Veracruz state that has yielded the skulls of at least 166 people, officials said Thursday.

Veracruz Attorney General Jorge Winckler Ortiz said the mass grave was found after a tip came in last month.

The search yielded 200 pieces of clothing, 144 IDs and personal belongings. Evidence indicated the deaths may have occurred a couple of years ago, he said in a statement.

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Authorities would not provide details on what may have occurred or where the site is located, given an ongoing investigation.

Veracruz, along with Nuevo León, Guerrero, Jalisco and Michoacán, are among the states where significant amounts of human remains have been discovered in mass graves.

Cartels such as Los Zetas, El Cartel del Golfo and Cartel Jalisco Nueva Generación have a heavy presence in those states. It hasn’t been confirmed that these findings are linked to any of them.

Genetic examinations of the remains will be matched with databases that include information on missing persons. Officials hope to post a catalog with photos of the clothing and identifications as early as next week. Winckler encouraged families with missing relatives to report them to authorities.

More than a year ago, in Colinas de Santa Fe, Veracruz, police found nearly 300 remains inside a mass grave.

Non-governmental groups and federal authorities have reported that there are more than 30,000 people reported missing in the country