Mexico's authorities say that two of the country's most powerful drugs cartels have overcome their rivalry¹ to form an alliance against a third.

墨西哥官员称，国内两个最具实力的贩毒团伙结束敌对状态，结成联盟以对抗其它团伙。

Nearly 18,000 people have died in drugs-related violence since 2006

Ramon Pequeno, head of the Mexican anti-narcotics（麻醉剂） police, said the Gulf² and La Familia cartels were now fighting a group called the Zetas.

They are fighting over a lucrative³（赚钱的，合算的） drug transit⁴（运输，经过） point on the US border.

The Zetas began as hitmen（职业杀手） for the Gulf cartel in the 1990s but recently pushed for their own share of the drugs trade.

Believed to have emerged from among Mexican army deserters（背弃者，逃兵） , they are notorious（声名狼藉的，臭名昭著的） for their readiness to behead（砍头，斩首） victims. Their criminal activities are believed to include drug-trafficking, extortion（勒索，敲诈） , migrant-smuggling and kidnapping（绑架，诱拐） .

Nearly 18,000 people have been killed in drugs-related violence in Mexico since 2006.

Some 40,000 soldiers have been sent to border regions to fight the cartels.

'War on everybody'

The shift in allegiances（忠贞，效忠） is apparently⁵ fuelling drug-related violence along Mexico's border with Texas.

Intelligence reports indicated the Gulf cartel had recruited（招募，雇佣） La Familia to crush the Zetas in the border state of Tamaulipas, said Mr Pequeno.

An official with the US Drug Enforcement Administration (DEA) said a third cartel, the Sinaloa, had also joined the alliance against the Zetas.

"It's an issue of a common enemy," Will Glaspy, head of the DEA office in the border town of McAllen, told the Associated Press news agency.

Banners began appearing in Tamaulipas earlier this year announcing the campaign by "the cartels of Mexico united against the Zetas".

One banner even urged President Felipe Calderon to withdraw the army and let the new alliance exterminate⁶ the Zetas, AP notes.

Another which was hung from bridges read: "The Gulf Cartel separates itself from the Z [ie the Zetas] in our ranks. We don't want kidnappers⁷, terrorists, bank robbers, rapists, child killers⁸ and traitors⁹."

Videos and e-mails were sent around warning families to stay at home, saying the conflict would get worse.

Mr Pequeno said that La Familia, whose stronghold（要塞，大本营） is in the Pacific coast state of Michoacan, had sent a large number of gunmen across the country to Tamaulipas to help the Gulf cartel wipe out（消灭，垮台） Los Zetas.

"The Zetas have been trying to wage war on（向……开战） everybody for a while," Mr Glaspy added.

"It's been well documented that the Gulf cartel has formed alliances with the Sinaloa cartel and [La Familia] to wage war against the Zetas."