Authorities have captured two top members of a major Mexican drug cartel (search) who ranked among the most-wanted suspects on both sides of the U.S.-Mexico border, Mexico's attorney general said Monday.

The U.S. Department of Justice had offered rewards of $2 million each for the capture of Jorge Aureliano Felix (search) and Efrain Perez (search), who were arrested last week in the La Mesa area of Tijuana, across the border from San Diego.

Attorney General Rafael Macedo de la Concha announced the arrests at a news conference.

Macedo said the men were the top operatives of the Tijuana-based Arellano Felix cartel (search), which the Justice Department has called "one of the most notorious multinational drug trafficking organizations ever." He said Perez may have been acting as leader of the group.

Officials say the Arellano Felix group dominated the world of Mexican drug trafficking in the late 1990s and developed a reputation as the most bloodthirsty of its major smuggling groups.

Benjamin Arellano, reputedly the planning chief of the drug group, was arrested in 2002. Another brother, Ramon, allegedly in charge of maintaining discipline and killing rivals, was shot to death earlier that year in the Pacific tourist port of Mazatlan.

In other strikes against the gang, police arrested a top lieutenant, Ismael Higuera, in 2000. The alleged financial operator for the group, Jesus Labra, had been arrested earlier that year.

Officials have said that control of the gang apparently fell to Francisco Javier Arellano Felix, the youngest of the family's six brothers, but Macedo said Monday that Perez may have exercised control.

Francisco Javier Arellano Felix is still at large.

Aureliano Felix was the organization's logistics chief in charge of security, he said.

Macedo said Perez's position in the cartel was confirmed by documents found in a drug-smuggling tunnel linking Tijuana to the United States that was discovered in 2002.

Perez and two other detainees were linked to a shipment of cocaine from Colombia that landed on a clandestine runway in Baturi, Mexico, Macedo said.

Seven other members of the Arellano Felix organization were arrested in the June 3 operation.

In November, Mexican authorities announced the capture of Jose Alberto Marquez, who is accused of having worked as a hit man for the Arellano Felix cartel.

U.S. authorities are trying to extradite the eldest Arellano Felix brother, Francisco Rafael Arellano Felix, who recently completed a 10-year sentence for stockpiling illegal weapons.

Perez and Aureliano Felix will be tried first in Mexico before facing extradition to the United States, Macedo said. They were in the process of being transferred to a maximum-security prison.

Macedo said they might be sent to the La Palma prison, Mexico's highest security facility, where Benjamin Arellano Felix is being held. Macedo acknowledged that federal authorities are responding to reports that prisoners at La Palma have been able to maintain contact and continue working with criminal organizations.

Macedo said cooperation with U.S. authorities played a part in the June 3 arrests.

Mexican authorities say they continue to focus on dismantling the Ciudad Juarez-based cartel lead by Vicente Carrillo Fuentes and the gang led by Ismael "El Mayo" Zambada, based in Mazatlan.