In an unusual public relations campaign, the Mexican drug cartel run by Chicago's so-called public enemy number one is denying involvement in a grenade attack on America's consulate in Guadalajara.

"El Mencho," the street nickname for Chicago's most-wanted drug kingpin Nemesio Oseguera-Cervantes, is suspected by authorities of orchestrating a double-grenade assault on the U.S. consulate two weeks ago today.

Across Guadalajara banners have been unfurled and hung from a dozen overpasses proclaiming that Mencho's cartel had no role in the bomb attack and that suggestions they were responsible are aimed at "sullying" the cartel's image. It is an oddly brazen denial for a criminal organization that authorities say routinely murders competitors, wayward customers, reporters and government officials; in some cases using beheadings and dismemberment to encourage compliance.

Read more: ABC 7