Hundreds of Mexican soldiers and police have taken control of a maximum security prison outside Mexico City to maintain order to head off violence among drug cartels or a possible prison break.
Some 750 troops and police Friday locked down La Palma prison, which holds reputed drug lords Osiel Cardenas, leader of Mexico's Gulf cartel, and Arellano Felix cartel head Benjamin Arellano Felix.
Authorities allege the two men had formed an alliance to battle the Juarez drug cartel, which officials say had been trying to take over drug routes throughout Mexico.
The security operation comes two weeks after Arturo Guzman, the jailed brother of escaped drug trafficker Joaquin Guzman, was gunned down at La Palma. Joaquin Guzman himself broke out of another facility in 2001.
The raid on Friday also follows the resignation of the head of Mexico's federal prisons, Carlos Tornero.
Some information provided by AP and Reuters.