One of the leaders of the Jalisco Nueva Generacion drug cartel is in custody, Mexican Attorney General Jesus Murillo Karam told reporters at the swearing-in of the AG office's new delegate in the western state of Jalisco.

"If we are talking about the same person, he is under arrest," Karam said in response to a question about the rumored detention of Victor Hugo Delgado Renteria, alias "El Tornado."

Media outlets in Jalisco said Delgado Renteria was apprehended last week during an army operation in Guadalajara, the state capital.

Jalisco Nueva Generacion arose following the 2010 death at army hands of Ignacio "Nacho" Coronel, a senior figure in the Sinaloa cartel, Mexico's most powerful criminal organization.

Apparently allied with the Sinaloa outfit, Nueva Generacion has been battling several other groups for dominance of drug trafficking in Jalisco.

Reflecting on the recent arrests of several major drug bosses, including the capture earlier this week of Los Zetas chief Miguel Angel Treviño Morales, Karam said "many" kingpins remained at large.

Treviño's arrest "is an important, indispensable step," the attorney general said, but it is "only one step in the quest for peace and tranquility."

Conflict among rival drug cartels and between criminals and the security forces has claimed more than 70,000 lives in Mexico over the last 6 1/2 years. EFE