Mexican marines have caught Mario Cardenas Guillen, an alleged leader of the Gulf Cartel, one of Mexico's most notorious drug trafficking organizations, and he was paraded on television Tuesday.

Known as "El Gordo" ("The Fat One"), Cardenas Guillen was holding a "large weapon" at a building entrance when he was captured Monday in Altamira, a city in the northeastern state of Tamaulipas, which borders Texas, the navy said.

He was "one of the main leaders" of the Gulf Cartel, said navy spokesman Jose Luis Vergara.

The marines confiscated the weapon plus three ammunition clips holding 30 bullets each, two grenades, 129,700 pesos ($9,850) in cash and four small plastic bags containing a white powder resembling cocaine, Vergara said.

The arrest deals a new blow to the Gulf Cartel, which has been weakened since it broke ties in 2010 with its hit men, the Zetas, who subsequently became a rival drug trafficking group.

After his release from prison in 2007, Cardenas Guillen and his brother Antonio Cardenas Guillen, or "Tony Tormenta," took control of the Gulf Cartel, Vergara told reporters.

But the criminal gang split into two factions after "Tony Tormenta" was killed in a shootout with Mexican troops in 2010, the spokesman said.

One side remained loyal to the Cardenas family while the other side pledged allegiance to Eduardo Costilla Sanchez, known as "El Coss."

Another brother, Osiel Cardenas Guillen, headed the cartel until his own capture in 2003. He was extradited in 2007 to the United States, where he is serving a 25-year prison sentence.

Mario Cardenas Guillen, who was hauled before television cameras and flanked by two masked marines, was arrested back in 1995 on charges linked to organized crime and drug trafficking.

He allegedly smuggled "large quantities of cocaine and marijuana" while he was locked up in Matamoros, a city bordering Texas. He was transferred to a prison in the western state of Jalisco in 2003 and released four years later.

Javier Oliva, a security expert at the National Autonomous University of Mexico, said the latest capture "is one of the most important arrests in recent years."

But he added: "It is a partial success because the production and consumption of drugs is not coming down."

Since President Felipe Calderon launched a military offensive against the cartels in December 2006, authorities have detained or killed 22 of Mexico's 37 most wanted drug traffickers.

But the last six years have also been marked by an upsurge of drug-related violence that, according to analysts, has left around 60,000 people dead.

The split between the Gulf Cartel and the Zetas sparked a brutal turf war that spread from Tamaulipas to the neighboring state of Nuevo Leon.

While the Gulf Cartel has lost power, the Zetas have grown stronger and extended their reach to 17 of Mexico's 32 federal entities, according to the Texas-based security analysis firm Stratfor.

The Zetas are battling the Sinaloa cartel for control of drug trafficking routes to the United States. The Sinaloa gang is headed by Joaquin "El Chapo" ("Shorty") Guzman, Mexico's most wanted man.