MEXICO CITY — A paramilitary group is vowing to "eliminate" the Zetas, reputedly Mexico's most violent drug gang, in a video posted on the Internet several days after 49 bodies were found on the streets of Veracruz.

The video, posted on Saturday according to its creators, shows a group of five masked men, dressed in black and seated at a white table, calling themselves the "Mata Zetas," or "Zeta Killers."

"Our intention is to let the people of Veracruz know that these dregs of society are not invincible," one of them says after offering "apologies" to the public and the authorities.

The men in black presented themselves as "the armed wing of the people, for the people," and highlighted their respect for Mexican authorities.

Last week the bodies of 49 people were found over a 48-hour period from Tuesday through Thursday in Veracruz, as the eastern port city was hosting a national conference of judges and prosecutors.

Thirty-five of the bodies were dumped under a busy overpass, and most of them were believed to have been Zetas cartel members with criminal records.

Mexican media said a message found near the bodies carried threats to the Zetas, who have been fighting for control of drug and human trafficking routes in the area.

The macabre displays were gruesome reminders of the new levels of violence plaguing the state of Veracruz, on the Gulf of Mexico, as the Zetas this year shifted their base of operations from neighboring Tamaulipas state, which borders the United States.

The Mexican government of President Felipe Calderon however rejected the unwanted help.

Anyone "outside the law that attempts to become a crime fighter lack the necessary legitimacy and ... will face the forces of the state," said Francisco Blake, the country's interior minister, said Tuesday.

The Zetas, set up in the 1990s by ex-elite soldiers turned hired killers, have been locked in a brutal turf war with their former allies in the Gulf cartel.

The syndicate has been blamed for several gruesome attacks, including the beheadings of 27 farm workers in Guatemala in May; the August firebombing of a Mexican casino which left 52 people dead; and the massacre of 72 migrants last year on a ranch in Tamaulipas.

Blake also said that the federal government "equally fights" all criminal groups -- a possible reference to photographs published by the daily Reforma suggesting that anti-drug raids by Mexican Marines favor the Sinaloa drug cartel of Joaquin 'Chapo' (Shorty) Guzman.

At least 41,000 people have been killed in Mexico's drug war since 2006, when the government launched a military crackdown on powerful cartels embroiled in turf wars marked by kidnappings, torture and mass graves.