Two high-ranking military officers have gone on trial in Mexico charged with having links to one of the country's most powerful drug-trafficking organisations, the Juarez cartel.

Division General Francisco Quiros and Brigadier General Mario Arturo Acosta are the first officers of such high rank to be court-martialled on drugs charges.

President Fox's crackdown seems to be achieving results

The Supreme Military Court has called a Council of War of five generals, all of them more senior than the accused, to hear the case.

Both men deny any involvement. Correspondents say they could face prison sentences of up to 40 years.

They are also facing separate accusations that they were involved in the deaths of 143 alleged guerrillas and left-wing activists during the violence in the 1960s and 1970s that became known as Mexico's dirty war.

They are expected to face a military court in this case along with retired Major Francisco Javier Barquin.

Innocence declared

Generals Quiros and Acosta were arrested in 2000 for allegedly protecting the Juarez cartel from army anti-drug operations.

The cartel, which was headed by drug baron Amado Carrillo Fuentes until his death in 1997, flew shipments of cocaine and marijuana to the United States.

Both generals declared their innocence and invoked their right to remain silent when asked questions by prosecutors.

"I cannot deny acts in which I did not participate and it's possible that the questions of the prosecution could be accusatory, which would mean lying," General Acosta told the council.

General Quiros said he intended to prove that the allegations made by protected witnesses were false.

Mexico is a major producer of cocaine and opium poppies, as well as being on key routes for shipments of cocaine from Colombia to the US.

But Mexican President Vicente Fox's recent crackdown on the drugs trade has been hailed as a success in many quarters, resulting in a decline in cocaine purity on American streets and cash flow problems for cartels.