Updated

Police have found three human heads in a roundabout near a small town in western Mexico where "self-defense" vigilantes have clashed with drug traffickers.

Michoacan state prosecutors say the heads were left along with a note near the town of Los Reyes. They wouldn't reveal the content of the message and didn't identify the victims.

Authorities said the heads found Thursday belong to males and that all had bullet wounds.

Self-defense squads have been forming in recent months in Michoacan by people who say they are fighting violence, kidnappings and extortions carried out by drug cartels.

Last month, police found the bodies of two men hanging from a tree in the town of Los Reyes along with a message threatening the community's self-defense group.