Mexican soldiers and police found 32 bodies and nine human heads buried in graves in southern Mexico after responding to a tip, authorities said Thursday.
One kidnapping victim and 12 bodies in coolers were also found at the site in Guerrero state.
No suspects have been detained, Reuters reported. It was unclear how long the remains, which were being transferred to the state capital of Chilpancingo to be identified, had been buried.
The Mexican state has been struck by violence from two rival cartels. Decapitations are typical among victims of gang-related retaliation.