On Monday , Calderon blamed fighting between rival cartels for the violence . Authorities say Mario Cardenas Guillen is a leader of the Gulf cartel . He was captured in a military operation Monday . The U.S. State Department says it has no information about his capture or whereabouts. His brother , Osiel Cardenas Guillen , was the cartel 's founder and former leader .
Authorities say Mario Cardenas Guillen is a leader of the Gulf cartel . He was captured in a military operation Monday . The U.S. State Department says it has no information about his capture or whereabouts. His brother , Osiel Cardenas Guillen , was the cartel 's founder and former leader .