Since late 2006, some 45, 000 soldiers have been deployed to take on the drug gangs.
The wealth and weaponry of the drug gangs dwarf the resources of the state.
The drug gangs' gunmen apparently retreated ahead of the operation and there appeared to be little resistance.
The drug gangs are anxious to avoid creating spillover violence, which would invite more attention from the American side.
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Under threats from the drug gangs, many media outlets make the choice to self-censor and not cover the violence.
Guatemala has struggled to deal with the violence generated by the drug gangs.
That kind of extra money to fund the drug gangs only worsens the balance of power between the state and the traffickers.
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At some point in this project, she had to negotiate with the drug gangs that began to take control of some of these favelas.
Earlier this year, the military was called in to help tackle the drug gangs operating in the neighbourhoods, and violence against women is particularly acute.
Having largely ignored Mexico's fight against the drug gangs for the past two years, American television has suddenly latched on to it, in sensationalist terms.
One of the most violent of the drug gangs, known as the Zetas, is made up of special-forces troops who changed sides a decade ago.
More than 60, 000 people have died in drug-related violence in Mexico since late 2006 when the previous government deployed troops to take on the drug gangs.
Mr Fernando is one of the founders of AfroReggae, a cultural NGO that has mediated in conflicts between the police, the drug gangs and favela residents.
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There has not been much progress against the drug gangs either, despite a great deal of help from the United States and a few big arrests.
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Mexico's government uses evidence at the crime scene such as decapitations or a sign left by an alleged cartel to distinguish crimes linked to the drug gangs from common murders.
As to whether the words will lead to practical co-operation, Mexican officials say they are getting more help with intelligence on the drug gangs from their American counterparts.
Mr Zedillo has had to face both a surge in petty crime, which is blamed on the economic crisis, and an increase in organised crime: especially in drug-trafficking, after the relative weakening of the Colombian drug gangs allowed more room for Mexican ones.
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His predecessor, Felipe Calderon, launched a war on the powerful drug gangs in December 2006.
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This now looks less of an advantage than it once did (and not just because it is Americans who arm and finance the Mexican drug gangs).
Mr Perez Molina, who ran unsuccessfully in the 2007 election, made tackling Guatemala's high crime rate and combating the presence of Mexican drug gangs in the country his priorities.
It is hardly surprising that the most powerful drug gangs should have moved from Colombia to within sight of the border: power lies closest to the consumer.
Take the policing of drug gangs in Rio de Janeiro's favelas.
She said she believes the spiral of violence began in May when the Sao Paulo state government took a more aggressive stance against the PCC and drug gangs.
The killings were all apparently related to the drug-trafficking gangs.
This is the third time the race has taken place in the Complexo do Alemao, a vast area of interconnected slums once ruled by some of the most powerful drug gangs in Brazil.
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They are the serious criminals leading the gangs responsible for drug dealing, human trafficking and fraud.
The government's count of deaths linked to drug gangs in the past few years has usually been about 25% higher than that of newspapers.
While illegal, the only person regulating drugs is the drug dealers and street gangs and cartels.
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It also needs jobs, if it is to prevent its youth joining the illegal economy of drug gangs and armed groups.
On a recent trip to Mexico, I strolled past kiosk after kiosk covered in a cascade of newspapers showing decapitated torsos and hanging bodies on the front pages -- the gruesome handiwork of drug gangs.
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