Police in western Mexico have discovered the bodies of 21 men.

Officials said Thursday the victims were found in various locations outside the city of Morelia in Michoacan state.

Police say the victims appear to be between the ages of 20 and 35 and some showed signs of torture.

Authorities say some of the bodies had warning notes attached. One read “here are the thieves, muggers and rapists, and there are still more to come.”

It was not immediately clear who was responsible for the murders.

Michoacan is the home state of Mexican President Felipe Calderon and has been the site of bloody drug-related violence. It is the base of the drug cartel known as La Familia.

More than 37,000 people have been killed in Mexico's drug-related violence since Mr. Calderon took office in late 2006 and began cracking down on the nation's cartels.