Violent clashes between Mexican drug traffickers and local police have climbed sharply in Tamaulipas state since March 14, when Gulf Cartel leader Osiel Cardenas Guillen was captured in Matamoros. Tamaulipas authorities have asked the Mexican federal government for urgent support to help fight organized crime gangs. Four suspected drug traffickers were killed and three wounded in a single day recently in gunfights with Mexican police just across the border from Roma, Texas. Also, police in Nuevo Laredo anticipate that a major bloodletting could erupt at any time between rival gangs fighting for control of the now leaderless Gulf Cartel. The capture of Cardenas Guillen stemmed largely from President Vicente Fox's aggressive counternarcotics strategy — systematically targeting Mexico's most notorious drug lords for arrest by focusing resources and efforts on one drug cartel at a time.