MEXICO CITY — Mexican forces backed by tanks and helicopters raided the maximum-security La Palma prison near here early Friday morning to thwart what officials called a possible planned escape of inmates held for drug trafficking.
The raid came amid a turf war at the prison, where many drug cartel leaders are imprisoned, and across Mexico, the main transit corridor for Colombian cocaine headed for the United States.
More than 750 Mexican army troops and police participated in the raid, and they are expected to remain for a week, Undersecretary of Public Security Miguel Angel Yunes told reporters outside the prison. Initial sweeps of inmates' quarters turned up two cellphones, small amounts of cocaine, 20 knives and a plasma TV screen.
On Friday afternoon, several army tanks remained around the prison, in Almoloya de Juarez, about 50 miles west of Mexico City, the capital. Officials said the government had decided to declare a state of alert and take control of the facility after receiving information that there were "grave risks to the physical integrity of some prisoners and the possibility of an escape attempt."
Last summer, Jose Luis Santiago Vasconcelos, deputy attorney general for organized crime, said police intelligence had indicated a breakout at La Palma was being planned, possibly involving the Zetas, a rogue team of specially trained army troops that had joined the so-called Gulf cartel headed by Osiel Cardenas. About one-third of the Zetas, who once numbered about 45, have been jailed or killed, but the rest remain at large.
Although La Palma is the highest-security prison in Mexico, three slayings took place within its walls last year.
The most recent was the New Year's Eve killing of Arturo Guzman Loera, brother of Joaquin "El Chapo" Guzman, one of the leaders of the so-called Sinaloa cartel. Two associates of Guzman were killed in La Palma earlier in 2004.
Federal officials said the alert would be maintained until there was "absolute certainty that maximum-security conditions have been restored and strict operational norms have been restored."
Army units remained outside the prison while members of two federal police units searched it.
Secretary of Public Security Ramon Martin Huerta on Friday announced the resignation of the federal director of prisons, Carlos Tornero Diaz. The warden of La Palma, Guillermo Montoya Salazar, and several other former prison staff members have been jailed in connection with the Guzman slaying.
Vasconcelos said Thursday that the warden had been jailed because his management of the prison violated legal norms.
The capture and killing of several drug mafia leaders in recent years has sparked a struggle for power among the half-dozen cartels vying for dominance of the cocaine transshipment racket.
Vasconcelos said Thursday that Tijuana cartel leader Benjamin Arellano Felix and Cardenas, leader of the Gulf cartel, both La Palma inmates, had recently formed an alliance to fend off challenges from Sinaloa. On Friday federal officials relocated Arellano Felix and Cardenas, whose cells had been close to each other, to opposite ends of the prison.
Ernesto Lopez Portillo, director of the Institute for Democracy and Security, a think tank in Mexico City, said the use of soldiers to restore order in the prison reflected the weakness of the nation's civil institutions in the face of drug traffickers.
"Mexico is living an intense process of militarization in confronting organized crime. Mexico is not alone in this -- you've seen it in Brazil as well," Lopez Portillo said. "But there are risks in this. You are exposing the army to the possibility they will be corrupted too."