Mexico City  - The break-up of the alliance between drug bosses including Joaquin "El Chapo" Guzman and Arturo Beltran Leyva has unleashed a war in Mexico for control of drug traffic which left 21 to 34 people dead on Sunday alone, Mexican media said Monday.

The killings represented an escalation of an already high level of violence in the country, particularly in the northern state of Chihuahua.

In Chihuahua, on the border with the United States, there were 12 murders on Sunday and 17 "levantones" - as kidnappings without the intention to demand ransom are known in Mexico.

According to the daily El Universal, the group of hired killers known as Los Zetas - until know the armed wing of the Gulf Cartel - formally agreed to become an independent cartel Sunday, at a meeting in the northern Mexican city of Torreon.

An official of the US Drug Enforcement Agency (DEA) told the daily, on condition of anonymity, that Los Zetas "can beat any cartel known currently known and become a real national security problem for Mexico and the United States."

Los Zetas is an armed organization created by deserters of the Mexican Army who has been for a decade in the service of the Gulf Cartel. The cartel was headed by Osiel Cardenas Guillen until he was extradited to the United States last year.

According to El Universal, two of the main leaders of Los Zetas - the former military officer Heriberto Lazcano, alias "El Z1," and Miguel Angel Trevino Morales - decided to become independent and form a new cartel, although other "zetas" are still active for the Gulf Cartel.

Government sources said the new organization, along with Beltran Leyva's, are fighting for control against "La Federacion" (the federation), an alliance of drug trafficking organizations led by "El Chapo" Guzman and by Ismael "El Mayo" Zambada, former allies of Beltran Leyva.

The split reportedly started in mid-2007, when Arturo Beltran Leyva negotiated with Zeta boss Lazcano without informing the other members of La Federacion.

In January, the authorities arrested Alfredo Beltran Leyva, alias "El Mochomo," in an action that his brother Arturo blames on a betrayal by Guzman - one of the most wanted drug bosses in Mexico, after he escaped from a high security prison in 2001.

"The alliance of Arturo Beltran Leyva and Los Zetas has turned (the state of) Sinaloa into a battlefield where Beltran is waging war against Guzman and Zambada in Culiacan, and against the brothers Carrillo Fuentes, bosses of the Juarez Cartel, in Navolato," the daily said.

In recent years Mexico has been shaken by violent actions between rival drug gangs and against security forces. According to media reports, some 1,100 people have been killed in such violence since January. (dpa)