Authorities in Mexico say the bodies of eight slain men were found on Friday dumped in Cosolapan, Oaxaca.
The prosecutor's office for Oaxaca state said in a statement that all eight victims were residents of the city of Córdoba in the neighboring state of Veracruz.
Officials say a warning message left with the bodies was signed by the pseudonym of a person who police allege is the head of a criminal group based in the Veracruz city of Orizaba. Authorities did not release the text of the threat.
Oaxaca officials say evidence indicates the eight men were killed in Veracruz and then transported to the dumping site.