A man believed to be the leader of the Gulf drug cartel, which controls some of the most valuable and violently contested smuggling routes along the US border, has been arrested by Mexican marines and presented to the public.
The capture of Jorge Eduardo Costilla Sanchez is a major victory in the military battle against drug trafficking, but it could open a power vacuum and intensify a struggle south of the Texas border in northeast Mexico.
The region has seen some of the most horrific violence in the country's six-year war among law-enforcement and rival gangs.
Admiral Jose Luis Vergara, a navy spokesman, said the burly, mustachioed man detained on Wednesday evening in the Gulf port of Tampico was the capo known as "El Coss".
One of Mexico's most-wanted men, the 41-year-old is charged in the US with drug-trafficking and threatening US law enforcement officials.
US authorities offered $5 million for information leading to his arrest.
Clad in a blue plaid shirt and bulletproof vest, the suspect was presented along with 10 bodyguards, five with bruised faces and clad in camouflage military fatigues similar to those of the marines who held them captive.
The navy also showed dozens of assault weapons, some pistols that appeared gilded and studded with jewels, and several expensive-looking watches seized in the operation.
"This is a very, very important arrest," said Guadalupe Correa-Cabrera, chair of the Department of Government at the University of Texas, Brownsville, and an expert on politics and crime in the Gulf Cartel's territory in the state of Tamaulipas.
She said the Gulf Cartel was a vertically structured organisation dependent on its top leaders, several of whom have been arrested in recent months.
Now, she said, she expects a surge in violence between the two remaining dominant cartels in Mexico - the Pacific Coast-based Sinaloa Cartel run by Mexico's most-wanted man, Joaquin "El Chapo" Guzman, and the brutal paramilitary Zetas, the former enforcement arm of the Gulf Cartel.
"It consolidates this new configuration of organised crime in Mexico," Correa-Cabrera said. "This disintegration of the Gulf Cartel will be impacting in a very serious way the levels of violence in Tamaulipas and probably in the whole country."
Vergara said five of Costilla's guards had been arrested Wednesday morning in Rio Bravo, Tamaulipas. Another five fled when marines tried to arrest them in Tampico, and the chase led authorities to Costilla's hideout, he said.
Costilla shook his head when asked if he had anything to say about the charges against him and when asked if he had a lawyer.
The Matamoros-based Gulf Cartel was once one of Mexico's strongest.
While it was badly weakened in recent years by battles with other gangsters and by law-enforcement operations, it smuggled and distributed tons of cocaine, methamphetamine, heroin and marijuana into the US under the leadership of the Cardenas Guillen family, three brothers who took over from one another as their siblings were captured or killed.
Costilla was born in Matamoros, across the border from Brownsville, Texas.
He worked for several years as a local police officer before allegedly joining the Gulf Cartel in the 1990s and becoming a lieutenant for then-leader Osiel Cardenas Guillen.
After Cardenas Guillen was arrested in 2003 and imprisoned in the US, officials say Costilla joined the capo's brother Ezequiel in running the cartel.
The tumult at the top prompted the powerful Sinaloa cartel to move in from its base along the Pacific Coast and launch a war for control of Nuevo Laredo, the busiest cargo crossing between the US and Mexico.
The Gulf won the fight, backed by a gang of assassins recruited from the Mexican military special forces.
Emboldened by their success in holding Nuevo Laredo, the enforcers known as the Zetas began asserting their independence and split from the Gulf Cartel in 2010 after the slaying of a Zeta member in the city of Reynosa, across from McAllen, Texas, that Costilla is believed to have ordered.