Mexican officials say that 33 people have been killed in the space of 24 hours in Mexico's industrial capital, Monterrey

Security officials in the northern state of Nuevo Leon, where Monterrey is located, said that most of those killed had links to Mexico's drug cartels. But two of the victims were identified as bodyguards of the governor of Nuevo Leon, Rodrigo Medina. Police said that a threatening message addressed to Medina had been found next to the bodies. Medina said that the threats would not stop his determination to beat organized crime. A spokesman for the Nuevo Leon Security Council, Jorge Domene Zambrano, said that the killings were almost all connected to a deadly battle for control of the region between rival drug cartels. According to authorities, five presumed gang members were killed in a battle with the army and 10 people died in a confrontation between rival gangs. The bodies of the remaining victims were found dumped in various parts of the city and, in some cases, hanged from bridges. The state is the stronghold of the Zetas, thought to be one of Mexico's most violent drug cartels. They are engaged in a deadly battle with the Gulf, Sinaloa, and La Familia gangs.