A major military operation in Mexico near the Texas border has netted another major drug trafficker, the government said, the second key gang boss capture in just over a month.

Mario Ramirez Trevino, known as X-20 or "The Bald One," was captured in Mexico's northern Tamaulipas state on Saturday morning, according to a statement.

Ramirez, a drug boss in Reynosa who had been vying to take over the cartel since the arrest of the Gulf's top capo, Jorge Eduardo Costilla, alias "Fatso,'" last September. Some say he succeeded, while others say the cartel continues to be split into factions.

Al Jazeera's Adam Raney, reporting from Mexico City, said Ramirez was a big catch for the Mexican government and that the news showed that gang bosses operating in the north of the country - a valuable smuggling route - were in the cross hairs of the security forces.

"The government is clearly going to be happy about this," he said. "Despite these arrests we're seeing large parts of the country controlled by very powerful, very violent drug gangs operating with impunity." 

Tamaulipas state government spokesman, Rafael Luque, confirmed that there was a major operation of the Mexican army and marines on Saturday afternoon with helicopters in the town of Rio Bravo. He could not confirm if anyone was killed, injured or detained.

The Gulf Cartel's power has waned in recent years in a feud with Mexico's most brutal gang, the Zetas, which began life providing protection to the cartel's operations in northeastern Mexico.

The US government had offered a $5m bounty for Ramirez, as Washington says his cartel controls most of the cocaine and marijuana trafficking to the United States from Matamoros in Tamaulipas state.

Mexico's marines last month arrested the leader of the Zetas, Miguel Angel Trevino, a few kilometres from his hometown of Nuevo Laredo on the US border.

More than 70,000 people were killed during former president Felipe Calderon's six-year offensive against drug cartels and over 6,000 have died since Pena Nieto took office in December.

On Sunday at least 23 bodies have been found in two neighbouring states in Western Mexico. Local authorities say nine of the corpses were found in an abandoned property near the town of Buenavista Tomatlan. 

Their hands were bound and they had been shot. A sign found with the bodies suggested the dead were members of the Knights Templar, a powerful drug cartel that controls the area.

Source: Agencies