Mexican authorities say they have arrested an alleged top member of the powerful Sinaloa drug cartel.
Police detained Jesus Zambada and 15 other suspects after a shootout in Mexico City, Mexico's Attorney General Eduardo Medina Mora told journalists.
Mr Medina Mora said Jesus Zambada directed cocaine trafficking through Mexico City's international airport.
Drug-related violence has soared in Mexico, with more than 3,500 deaths reported so far this year.
Jesus Zambada Garcia, known as "the King", was detained along with the other suspects after a clash with police on Monday.
He gave a false name and police were initially unaware that he was among the detainees, Mr Medina Mora said.
Several federal police were among those detained.
"He is one of the most important importers of cocaine and methamphetamine to this country from South America," Marisela Morales, head of the organised crime division in the attorney general's office, said.
The Sinaloa is reportedly led by Joaquin "Shorty" Guzman, one of Mexico's most wanted men.
Jesus Zambada's brother, Ismael, is also alleged to be one of the cartel's main figures.
The cartel has suffered a number of blows since President Felipe Calderon began deploying troops two years ago in an attempt to tackle the drug gangs.
But murders and killings linked to the drugs trade have surged.
Fighting between rival gangs as they battle for control of lucrative drug routes has become ever more brutal, while attacks on police have also increased.