Mexico captures Sinaloa cartel leader Damaso Lopez

This frame grab from video shows Damaso Lopez, known by the nickname "El Licenciado," escorted by police after his capture at an upscale apartment building on a major boulevard in Mexico City, Tuesday, May 2, 2017. Mexican prosecutors said they captured Lopez, one of the Sinaloa cartel leaders who launched a struggle for control of the gang following the re-arrest of Joaquin "El Chapo" Guzman. Lopez was long considered Guzman's right-hand man and helped him escape from a Mexican prison in 2001. (AP Photo/Jorge Barrera, APTN) (The Associated Press)

The apartment building where Damaso Lopez, nicknamed "El Licenciado," was captured in the Anzures neighborhood of Mexico City, Tuesday, May 2, 2017. Mexican prosecutors said they captured Lopez, one of the Sinaloa cartel leaders who launched a struggle for control of the gang following the re-arrest of Joaquin "El Chapo" Guzman. Lopez was long considered Guzman's right-hand man and helped him escape from a Mexican prison in 2001. (AP Photo/Marco Ugarte) (The Associated Press)

Security agents escort Damaso Lopez, nicknamed "El Licenciado," sitting inside truck behind right, outside an apartment building in the Anzures neighborhood of Mexico City, Tuesday, May 2, 2017. Mexican prosecutors said they captured Lopez, one of the Sinaloa cartel leaders who launched a struggle for control of the gang following the re-arrest of Joaquin "El Chapo" Guzman. Lopez was long considered Guzman's right-hand man and helped him escape from a Mexican prison in 2001. (AP Photo/Marco Ugarte) (The Associated Press)

Mexican prosecutors say they have captured one of the Sinaloa cartel leaders who launched a struggle for control of the gang following the re-arrest of Joaquin "El Chapo" Guzman.

The attorney general's office says it had detained a drug gang leader it called "Damaso N."

A federal official confirmed he's Damaso Lopez.

Lopez is believed to be locked in a dispute with Guzman's sons for control of the cartel's territories.

Guzman was extradited to the United States earlier this year to face drug charges.