MEXICO CITY - They tout themselves as self-effacing saviors, spilling still more blood as patriotic tribute to their already-lacerated homeland.

"We are the armed wing of the people and for the people," a ski-masked man intones in a videotaped declaration explaining his group's recent murders of as many as 49 people in the Gulf Coast port of Veracruz. "We are anonymous warriors … proudly Mexican."

The man condemns their victims as members of the brutal Zetas gang, which has branched out from drug running and assassination into extortion, kidnapping and other maladies. Their deaths will prove the first of many, the speaker suggests. Offering "respect to the armed forces, which we understand cannot act outside the law," the man says his brethren, the Zeta Killers, will inflict vengeance "to the benefit of the Mexican nation."

But the Veracruz killings and other incidents raise the specter of social and political goals seeping into what until now has been purely a contest for illicit gain. That could herald an even deadlier phase in a country where violence has taken upward of 45,000 lives in the last five years.

"This is a paramilitary group against another paramilitary group," said Samuel Gonzalez, a former senior federal law enforcement official who warns of a looming "civil war" for territory and markets. "We haven't had this kind of clear evidence of their existence until now."

"Paramilitary" is a loaded word in Latin America, referring to conservative private militias operating with the connivance and often active cooperation of government officials and private enterprise.

Such groups surged a generation ago in Colombia - financed by drug lords, wealthy ranchers and business executives enraged at kidnapping and extortion by leftist guerrillas. They greatly spiked the body count in that country's struggle with insurgents and gangsters.

"If the Mexicans thought it couldn't get any worse, this is obviously an extremely worrying development," said Michael Shifter, president of the Inter American Dialogue in Washington, D.C., who is an authority on Colombia's violent journey.

"It starts as the defense of private interests that are not defended adequately by the government," Shifter says. "Then it becomes a Frankenstein, out of control."

President Felipe Calderon's spokeswoman dismissed the killers as common gangsters, "delinquents of a band trying to take over the criminal activities of another group."

"Up until now, there's no evidence to imply that this criminal group can be defined as paramilitary," spokeswoman Alejandra Soto said.

Claiming to protect

In the Pacific resort of Zihuatanejo on Thursday, banners announced that the Knights Templar from Michoacan state had arrived in town to confront "kidnapping and all kinds of extortion." Promoting a quasi-religious philosophy despite their criminal transgressions, the gangsters long have claimed to protect the communities in their home state.

As Mexico's violence worsened in recent years, some rural towns set up self-defense brigades and suburban mayors their own spy networks. Neighborhood residents have taken to lynching suspected thieves and rapists. Some criminal bands long have promoted themselves as "the good bad guys," smuggling drugs to the United States but leaving local citizens in peace.

"It responds to the failure of the federal and state security forces to provide protection," said Bruce Bagley, a political scientist at the University of Miami who tracks organized crime in Colombia and Mexico. "It's rival groups acting outside the control of government of any sort. It becomes the source of still more violence."

The Zetas themselves set the Mexican standard for militarized crime. Founded by former soldiers, some of them special forces, the gang hired on as killers for the Gulf Cartel in the late 1990s, specializing in lightning raids on opponents. Other gangs geared up to take on the Zetas, buying better guns, hiring more mercenaries, training recruits.

Knights Templar, the Zetas rivals, soon took on aspects of militias, claiming to defend local towns from the gang. Mexico's other cartels have carved up the country into zones of influence.

"If you have economic power and military power, then by default you have political power," said Robert Bunker, one of the security analysts at the U.S. online publication Small Wars Journal who argues Mexico suffers a criminal insurgency. "That is a politicized social perspective that insurgents would have or paramilitaries would have."

Saying they're from a criminal band called the Jalisco Cartel-New Generation, the Zeta Killers warned in July they intended to take Veracruz away from the Zetas.

Victims shrugged off

The bodies dumped over several days last week around Veracruz seem a down payment on that promise. Veracruz Gov. Javier Duarte and other officials shrugged off the victims as criminals.

Just one of the 35 nude or scantily clothed victims left on a busy interchange had been shot, according to Mexican press accounts of the coroner's report. The others died of suffocation from being crushed into an air-less space. Some evidenced burns from hot metal objects.

"Our intention was to show the people of Veracruz that this scourge against society is not invincible," the masked Zeta Killer leader says in the group's video.

dudley.althaus@chron.com