Mexico City: Battles between the vicious Zetas gang and other drug cartels killed more than 40 people in a 24-hour span, a government official said on Sunday.
At least 20 people were killed when gunmen opened fire in a bar late Friday in the northern city of Monterrey, where the gang is fighting its former ally, the Gulf Cartel, said federal security spokesman Alejandro Poire.

Eleven bodies shot with high-powered rifles were found earlier on Friday, piled near water well on the outskirts of Mexico City, where the gang is fighting the Knights Templar, Poire said. That is an offshoot of the La Familia gang that has terrorised its home state of Michoacan.
He said another 10 people were found dead early Saturday in various parts of the northern city of Torreon, where the gang is fighting the Sinaloa cartel headed by Joaquin  "El Chapo" Guzman.

"The violence is a product of this criminal rivalry surrounding the intent to control illegal activities in a community, and not the only the earnings that come with it, but also with transporting drugs to the United States," Poire said in a news conference.
He repeated the government insistence that the criminals, not the government's crackdown on organized crime, are causing the violence. More than 35,000 people have died since President Felipe Calderon stepped up the attack on organized crime in 2006, according to official figures. Some groups put the number at more than 40,000.