The cartels also fight Competition for the control Control of local drug markets and extortion rackets , including shakedowns of migrants seeking to reach Arriving the United States .

In addition , the discovery Know seems to echo several other mass murder Killing events where the drug cartels have left Departing large numbers of bodies in public places as warnings Warning to their rivals Competition .

although the government crackdown of the drug cartels dates back to 2006 , monterrey became Becoming an increasingly violent city in 2010 , due Causation to the rupture of the gulf cartel and los zetas .

The fight Hostile_encounter was between Los Zetas and the Gulf Cartel , two drug cartels that operate Being_in_operation in northeastern Mexico .

Each cell block contained Containing roughly 750 inmates , with members of rival drug cartels normally separated Forming_relationships .