James McKinley reports for the New York Times April 16 that cartel wars for control of Ciudad Juárez are reaping a "Wild West Blood Bath" in the border city, with more than 210 lives lost in the first three months of this year. The number of homicides this year is more than twice the total number for the same period last year. Mass graves hiding a total of 36 bodies have been discovered in the backyards of two raided cartel safe-houses. At the height of the violence, around Easter, bodies were turning up every morning—at a rate of nearly 12 a week. Mayor José Reyes Ferriz and Chihuahua state authorities have asked the federal government to intervene. "Neither the municipal government, nor the state government, is capable of taking on organized crime," Reyes Ferriz said. In late March, President Felipe Calderón sent in 2,000 soldiers and 425 federal agents, who patrol in convoys of Humvees and pickup trucks, wearing ski masks to hide their faces.

Since the late 1980s, the border city's drug trade has been controlled by the Juárez Cartel, led by Vicente Carrillo Fuentes following the death of his brother Amado in 1997.* The recent violence stems from a gang war between former allies. On one side is the Carrillo Fuentes family and its local pointman, José Luis Ledezma AKA JL. On the other are traffickers based in Sinaloa state (often dubbed the Sinaloa Cartel), led by Joaquín Guzmán AKA El Chapo, and Ismael Zambada AKA El Mayo, according to a federal prosecutor who spoke on condition of anonymity. Their uneasy alliance has been strained since Rodolfo Carrillo Fuentes was assassinated in September 2004—allegedly on the order of Guzmán.

One theory holds that the tension reached a breaking point in December when Zambada refused to pay the Juárez Cartel a tax for moving drugs through its area. Since then, Zambada and Guzmán have opened an offensive against the Juárez Cartel. "Mayo and Chapo's people wanted to invade, and JL was not going to let them, and so the battles started," the prosecutor said.

One Mexican intelligence officer, also speaking anonymously, said that since the assassination of Rodolfo Carrillo Fuentes, the Juárez Cartel has forged an alliance with the Gulf Cartel, led by the imprisoned kingpin Osiel Cárdenas Guillén and his lieutenants in Tamaulipas state, across the border from South Texas.

John Riley, the special agent in charge of the Drug Enforcement Administration office in El Paso, said alliances among various factions shifted constantly, creating a chaotic situation for law enforcement. "A lot of these lines have been blurred since the first of the year," he said. "It's extremely confusing."

City officials said that Ledezma has recruited local street gangs like Los Aztecas as gunmen and enforcers, while the Gulf Cartel has brought in its own corps of hired hit men, the Zetas.

Officials say Ledezma has also infiltrated the local police department to an alarming degree. Most of the officers killed in the recent violence had links to drug traffickers, prosecutors said. Federal authorities arrested nine city police officers in late March on drug trafficking charges, and the former police commissioner, Saulo Reyes, was arrested in El Paso in January on charges of marijuana trafficking.

For residents, the federal police and military patrols have brought a brief respite from the state of terror. But in interviews several told the Times they remain afraid to leave their homes at night or to let their children play outside. Gunfire is still a common sound after sunset, they said.

*In addition to misspelling Vicente Carrillo Fuentes' first name as the Anglicized "Vincente," McKinley appears to have also got his relation to Amado Carrillo Fuentes wrong. By most accounts, they were father and son, not brothers.

See our last posts on Mexico, and the narco crisis and the struggle for the border.