The main suspect in the drug-cartel massacre of 27 farmworkers and relatives in Guatemala's Peten province was arraigned Friday on charges including conspiracy to murder and kidnapping.

Suspect Hugo Gomez Vasquez has been identified as a local leader of the Mexico-based Zetas drug cartel and a former member of the elite Guatemalan military unit known as the "Kaibiles."

He said he is innocent.

"I know the charges are serious, but given that I haven't done anything, I don't fear anything," Gomez Vasquez told The Associated Press at the hearing.

He also faces charges of illicit association and obstruction of justice. All the charges together carry a maximum prison sentence of 50 years.

The suspect was led into court wearing a bulletproof vest, and the judge ordered him held at a maximum-security prison pending trial.

"They picked me up because I was in the military," Gomez Vasquez said. "The government is picking up ex-military people." He added, "I've never been involved in any gang; I'm a farmer."

Court records indicate Gomez Vasquez was charged with attempted murder in another case in 2008, but the case was transferred to a different court and it was unclear whether he had been acquitted.

Twenty-five of the 27 victims in last weekend's massacre were decapitated. Most were employees of a rural ranch, and police believe the mass killing was a drug-related revenge attack aimed at the ranch's owner, who was not present when gunmen attacked late Saturday.

Prosecutors presented some of the evidence against Gomez Vasquez, including taped telephone conversations in which he allegedly negotiated a ransom demand in the kidnapping of a relative of the ranch's owner and her husband. Both were killed and decapitated before the weekend massacre.

Also Friday, Guatemalan President Alvaro Colom said evidence indicated that Guatemalan members of the Zetas were responsible for the massacre, and there was no indication any Mexican members of the cartel were involved.

The Zetas cartel started in Mexico and has spread its operations into neighboring Guatemala.

Colom told a Mexican radio station Friday that the flow of illegal weapons to drug cartels should be cut off to prevent further killings.