The bodies of seven men were found in the sitting position in plastic chairs alongside a street in western Mexico.
Authorities said the victims had been shot in the head and placed near a traffic circle in Uruapan, a city in Michoacan state.
A sign nailed to one of the bodies with an ice pick said: "Warning! This will happen to thieves, kidnappers, sex offenders and extortionists."
The gruesome discovery on Saturday came after seven people, including three off-duty federal police, were shot dead in a bar in neighboring Guerrero state on Friday night.
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