Gustavo Rivera Martinez, a U.S. citizen wanted by the FBI and the Drug Enforcement Agency (DEA) on drug charges, was arrested late on Tuesday in the northwestern Mexican state of Baja California Sur, Interior Minister Juan Camilo Mourino told a news conference.
The U.S. ambassador to Mexico, Tony Garza, sent a brief statement praising the arrest, the second major drug capture this year under President Felipe Calderon's crackdown on smugglers, after the detention in January of a senior operative of the rival Sinaloa cartel.
Tuesday's capture followed half a dozen recent raids on the Tijuana cartel, also known as the Arellano Felix organization, that have put around 30 mid-level operatives behind bars.
Rivera Martinez is described as a lieutenant-level manager by the DEA, which had offered up to $2 million for information leading to his arrest. He is believed to be close to Enedina Arellano Felix, the latest in a clan of siblings to be heading the cartel, based in and around the seedy border city.
Rivera Martinez "focused his operations in drug trafficking and money laundering," Mourino said, adding that he would be flown to the United States immediately.
Two of his accomplices were also arrested on Tuesday.
The once-mighty and notoriously violent Tijuana cartel has been weakened in recent years by a series of arrests or killings among the brothers who have taken turns running it.
A police raid last week on a suspected Tijuana cartel safe house turned up one of the largest arsenals of weapons ever seen in Mexico, including guns encrusted with gold figures or skulls.
"The Calderon administration's policy of pursuing the heads of these criminal organizations continues to bear fruit," Garza said of Rivera Martinez's capture.
Calderon sent out some 25,000 soldiers and federal police to battle the country's drug gangs after taking office in December 2006, and ramped up the army presence in Tijuana in January to curb a spike in drug-gang violence.
Nationwide, drug violence killed more than 2,500 people last year and murders so far this year total well over 300.
As Washington pledges of greater cooperation in the drug war, the U.S. Congress is debating the first chunk of a $1.4 billion aid package proposed by President George W. Bush last year to fund new surveillance equipment for Calderon's drug gang operation.
In January, soldiers arrested Alfredo Beltran Leyva, a close aide of Joaquin "Shorty" Guzman, Mexico's most-wanted man and head of an alliance of smugglers based in Sinaloa state.