Mexican authorities said Wednesday that they arrested a leading drug figure known as El Rey after a shootout in Mexico City early this week.
Jesus Zambada Garcia, the brother of a suspected drug kingpin in the western state of Sinaloa, was among 16 people captured Monday, Atty. Gen. Eduardo Medina Mora said.
The attorney general said Zambada, whose nickname means "the king," commanded one of four branches of the so-called Sinaloa cartel, leading its operations in central Mexico. Zambada is the brother of Ismael Zambada and an associate of Joaquin "Shorty" Guzman, the most-wanted trafficker in Mexico, officials said.
Jesus Zambada controlled smuggling of cocaine and chemical ingredients for the production of methamphetamine through Mexico City's airport, Medina Mora said. Authorities have focused attention in recent months on drug smugglers' use of the country's largest airport.
Zambada has also been linked to gruesome drug killings in central and western Mexico, prosecutors said.
"The arrest of Jesus Zambada Garcia, the King, stands out, without a doubt, as one of the most significant by President [Felipe] Calderon's government to date," Medina Mora told reporters. "It is not the only one in recent months, nor will it be the last in the months to come."
Investigators are looking into Zambada's possible role in the assassination of acting federal Police Chief Edgar Millan Gomez. The police commander was ambushed in May by a gunman in his Mexico City home, and authorities have long suspected that Sinaloa cartel traffickers were behind the slaying.
Marisela Morales, who runs the organized-crime unit of the attorney general's office, called Zambada "one of the most important" smugglers of cocaine and methamphetamines into Mexico.
Zambada's arrest offered officials a much-needed chance to claim progress in their uphill battle against drug traffickers.
Calderon declared a crackdown nearly two years ago, but drug-related violence has worsened despite some high-profile arrests and hefty drug seizures.
The death toll this year has exceeded 3,500, according to unofficial tallies in the media, amid a wave of killings that has included decapitations, scorched bodies and a growing list of innocent victims.
A grenade attack that killed eight civilians last month in the western state of Michoacan fed an increasing sense among Mexicans that their government is losing its war with well-armed drug gangs.
In Monday's incident, police came under fire after being led to a house in northern Mexico City by a resident's tip. Police rounded up the 16 suspects but were not able to immediately confirm Zambada's identity, Morales said.
Prosecutors said Zambada's 21-year-old son, Jesus Zambada Reyes, and a nephew were among those arrested.
On Wednesday, authorities lined up suspects and their seized weapons before news cameras, and police searched the house where the shootout took place.
U.S. Secretary of State Condoleezza Rice on Wednesday began a two-day visit with Mexican officials in the resort city of Puerto Vallarta that was to include discussion of Mexico's battle against traffickers.
Mexican officials are eager for the release of a $400-million package of U.S. training and equipment, known as the Merida Initiative.
The aid, approved by Congress in June, is the first part of a three-year assistance package for Mexico, Central America and the Caribbean.
In voting for the aid, Congress softened human rights prerequisites that had raised the hackles of Mexican officials. Lawmakers had attached the requirements to ensure that the aid would not be used to repress ordinary Mexicans or fall into the hands of corrupt authorities.
The two nations must reach agreement on final details of the assistance before it is delivered.
Previous coverage of Mexico's drug war is available online.