Mexico's federal Attorney General's Office says two nephews of a leader of the powerful Sinaloa drug cartel have been arrested on drug possession charges.

A spokesman for the agency says Omar Ismael Zambada and Sergio Rodolfo Cazares Zambada were detained Wednesday evening in the border city of Tijuana on suspicion of smuggling 15 kilos of cocaine. The spokesman spoke Thursday under the agency's rules barring him from being quoted by name.

The spokesman says the uncle of the two suspects is Ismael "El Mayo" Zambada. He is one of the leaders of the Sinaloa cartel, whose head is Joaquín "El Chapo" Guzman, the most-wanted man in Mexico.