Gunmen dumped the mutilated bodies of two bodyguards assigned to a Mexican state governor on Wednesday and left a message threatening more violence but the governor said he would not be cowed.
In an escalation of already alarming violence in Monterrey, Mexico's richest city, soldiers and police found the bodies wrapped in sheets and discarded near a supermarket, Mexican media and the government of Nuevo Leon state said.
"To Governor Rodrigo Medina, here are two of your bodyguards," read a message left near the bodies, according to local newspaper El Norte. The message also said the bodyguards, members of Nuevo Leon's state police, took money from the feared Zetas drug cartel.
"Let's see where the hell you can hide," it added.
The state government confirmed the deaths but did not give more details.
Medina, a member of the opposition Institutional Revolutionary Party, or PRI, is under pressure from citizens to put an end to the spiraling drug violence. On his Twitter account, he said he would not be cowed by the menace.
"The threats won't stop me from fighting for a safe Nuevo Leon," he said.
Medina later offered his condolences to the victims' families at a news conference but declined to provide more information about the attack or the bodyguards' names.
Monterrey is home to some of Latin America's biggest companies and its annual income per capita is double the national average at $17,000. But it has become one of Mexico's most violent cities with more than 650 drug war deaths so far this year, more than in all of 2010.
Once considered a model city, the manufacturing center of 4 million people 140 miles (230 km) from Texas has witnessed a rapid increase in drug violence since President Felipe Calderon began his fight against the cartels in late 2006. Some 40,000 people have died across Mexico since then.
The Zetas are fighting an alliance of the Gulf and Sinaloa cartel for control of Nuevo Leon and its smuggling routes into the United States.