At least 21 bodies have been found strewn in the streets just outside the western Mexican city of Morelia, and in every case the perpetrators left a warning note, the state prosecutor told AFP. The bodies, all males between the ages of 25 and 30, were found in different areas just outside the city limits of Morelia, in Michoacan state, said state prosecutor Jesus Montejano. Taking the unusual step of releasing the contents of the warning notes, Montejano said the message was: \"Because society asked for it, this is going to happen to those who continue to rob houses, kidnappers and rapists.\" Police said some of the bodies were found piled together, their faces covered by tape, in areas around the city, and some showed signs of torture. Michoacan state is the base of the notorious drug cartel La Familia, which is known for its religious zeal, notably justifying the beheadings of 12 policemen last June as being the work of \"divine violence\". Late last year the group said in a letter sent to local media it was ready to dissolve itself if security was enforced and citizens of the state are protected, urging the authorities to take control of the state \"with force and decision.\" Federal officials said it was unclear at the time whether the message was authentic, but still dismissed it, insisting the government \"could not make deals with criminals.\" The state has meanwhile seen an exodus of people fleeing their homes in recent weeks due to fighting between drug gangs and with security forces. Esquivel Lucatero, the mayor of Buenavista municipality, told AFP in late May that nearly 2,000 people had left their homes, as army helicpoters were deployed in the western state and soldiers maintained a heavy presence in the region. Authorities had set up a refuge for the families in Buenavista, in at least the second exodus due to drug violence in less than a year, after several hundred people fled their homes in Ciudad Mier, northeast Mexico, last November. The La Familia drug gang dominates Michoacan, but it was unclear whether intensified clashes were sparked by infighting within the gang or with other groups, such as the Zetas, which are expanding across the country. Mexico has seen an explosion in drug-related violence in recent years that has left some 37,000 people dead since the government launched a military crackdown on organized crime in 2006. In a brutal attack in the northern border state of Coahuila earlier this week, 13 people were killed after an armed gang stormed a drug rehabilitation center and fired on patients.