Amid the violence, U.S. Secretary of State Hillary Rodham Clinton indicated Thursday that the United States is committed to the Merida Initiative, a $1.4 billion funding package aimed at helping Mexico train and equip its anti-drug efforts.
Mexico is facing a huge challenge, and late Thursday Interior Secretary Fernando Gomez Mont said the government was pouring 1,500 federal police officers, 2,500 soldiers and 1,500 navy personnel into Michoacan state, the home base for the violent La Familia cartel.
The force, which will bolster several hundred federal security officers already in Michoacan, will be backed by at least three Black Hawk helicopters and three armored vehicles.
Last weekend's attacks by La Familia drug cartel were a blatant challenge to President Felipe Calderon, who has deployed about 45,000 soldiers and tens of thousands of federal police across the country in an attempt to halt the escalating drug trade.
Such measures have raised the concerns of human rights organizations, which have alleged cases of abuse by authorities.
Asked whether that could hurt future U.S. aid to Mexico's drug-fighting efforts, Clinton replied, "What we see here is an administration under President Calderon locked in a very difficult battle with the most ruthless drug traffickers and criminal cartels anywhere on the planet."
"We have worked very closely with his administration to provide additional support for police training and it is our assessment that the steps taken and the commitment demonstrated by the Calderon administration is deserving of confidence," she added at a joint news conference in Washington with Mexican Foreign Minister Patricia Espinosa.
La Familia cartel launched its coordinated offensive in Michoacan and two neighboring states Saturday within minutes of the arrest of its reputed operations chief, Arnoldo Rueda. In the worst attack,, their tortured bodies piled along a roadside as a warning for all to see. Six federal police officers and two soldiers were killed in other attacks.
Calderon insists the backlash from the cartel in response to Rueda's capture proves the drug gang has been weakened, but government critics said it revealed how vulnerable federal forces are to heavily armed crime organizations with intelligence networks within the police.
The buildup in Michoacan is already drawing troops away from other drug-violence hotspots. Nearly 2,000 federal police currently stationed in the drug-plagued northern border city of Ciudad Juarez will be sent south to help combat La Familia, local officials said Thursday.
On Wednesday, a man claiming to be La Familia leader Servando "La Tuta" Gomez called the CB Television station in Michoacan to offer a pact with the government. The man said the gang's wave of attacks is only a response to police action against cartel members' family and friends.
Federal officials said Wednesday that they were trying to confirm whether the caller was indeed Gomez. But the interior secretary, Gomez Mont, said that even if it was, the "federal government does not ever dialogue, does not negotiate, does not reach deals with any criminal organization."
Officials have named Gomez as the cartel leader who ordered the weekend attacks, and federal prosecutors have offered a reward of more than $2 million for information that leads to his capture. Authorities say Gomez assumed operational control of La Familia after Rueda Medina's arrest.
The caller claiming to be "La Tuta" issued a rambling defense of La Familia's actions, saying federal police and prosecutors "come and fabricate guilty charges."
"They are targeting innocent people in Michoacan state," he said.
Federal police have arrested and charged eight mayors in Michoacan for allegedly aiding the cartel and also have arrested leading drug traffickers at events including baptism parties for relatives. But Gomez Mont denied that traffickers' families were being targeted.
The weekend attacks spread quickly to at least 10 cities, including towns in Michoacan's neighboring states of Guerrero and Guanajuato. Officers' hotels were shot up and grenades were tossed at police posts.
In Guerrero, La Familia gunmen killed a federal police chief Tuesday. On Wednesday, authorities detained four people supsected in the killing, including Francisco Sotelo, the 18-year-old nephew of "La Tuta," state prosecutor Carlos Zamarripa said.
Federal prosecutors also announced Thursday the arrest of a retired army captain suspected of selling government weapons to the Beltran Leyva drug cartel. It is the first suspected case of weapons sales between the army and a drug cartel, according to a statement from the Attorney General's Office.
Mateo Juarez, a retired first captain, is also suspected of training soldiers to become hit men or bodyguards for the cartel, the statement said. Juarez was arrested July 14 during "Operation Clean House," an investigation that began in 2008 after reports that drug cartels had infiltrated security forces and prosecutors' offices.
The drug war has left more than 11,000 people dead since Calderon took office in 2006.