Mexico's federal police on Thursday announced the arrest of the Gulf drug cartel's purported No. 2 in the northern city of Monterrey and six of his close associates, officials said.

Salvador Roman Garcia, alias "El Tio," was arrested Tuesday on Bernardo Reyes Ave. in Monterrey, the capital of Nuevo Leon state, "while visibly armed on board a vehicle," the federal Public Safety Secretariat said.

The arrest of the 47-year-old suspect comes less than three weeks after the Sept. 1 detention of the Gulf mob's top boss in Monterrey, David Rosales Guzman.

"The lines of investigation indicate (Roman Garcia) was the alleged operational logistics head for drug distribution, and coordinated kidnappings and killings of members of rival gangs, mainly 'Los Zetas,'" which the Gulf mob is battling for control of the region, the statement said.

Another six people were arrested in the same action along with Roman Garcia, two linked to homicides and four suspected of working as informants for the criminal gang.

Actions attributed to the group include attacks on the "Elefante" and "Woman" bars in Monterrey on Feb. 7 and March 9, respectively.

The gang also is suspected in the slayings of two people on July 30 in that same industrial city, another homicide on Aug. 28 in the city's San Bernabe neighborhood, and three others on Sept. 5 in the Monterrey suburb of Santa Catarina.

The detainees also are linked to a Sept. 4 bomb attack that targeted members of a newly created Nuevo Leon state police force.

In Tuesday's operation, the federal police confiscated three vehicles, an assault rifle, two shotguns, ammunition clips, ammunition, a grenade, communications gear and drug-like substances.

These latest arrests bring to 17 the number of Gulf cartel-linked suspects detained this month in Nuevo Leon state.

Also this month, Jorge Eduardo Costilla Sanchez, the Gulf cartel's top boss and one of the most-wanted men in Mexico and the United States, was captured by marines with no resistance.

Costilla Sanchez, known as "El Coss," was arrested Sept. 12 at a house in Tampico, a port city in the neighboring state of Tamaulipas, the cartel's stronghold.

The capture was attributed to naval intelligence work and information obtained from two other Gulf cartel members arrested recently, including Mario Cardenas Guillen, the leader of one of the two branches of the criminal organization.

The Gulf cartel, one of Mexico's oldest drug trafficking organizations, was founded by Juan Nepomuceno Guerra in the 1970s and was later led by Juan Garcia Abrego, who was arrested in 1996 and extradited to the United States.

Osiel Cardenas Guillen took over the cartel's leadership in July 1999, but he was arrested in 2003. He continued running the Gulf cartel, one of the most violent criminal organizations in Mexico, until his extradition to the United States on Jan. 20, 2007.

He was succeeded by his brother, Antonio Ezequiel, known as "Tony Tormenta."

Antonio Ezequiel Cardenas Guillen was killed in a shootout with marines on Nov. 5, 2010, and Costilla Sanchez had been running the cartel since that time.

The Gulf cartel is no longer as powerful as it was in the past, partly because of its break with Los Zetas, the criminal organization's former armed wing, which severed ties with the cartel in 2010 and now runs its own narcotics trafficking business.

The Gulf organization, which mainly deals in cocaine, synthetic drugs and marijuana, mostly operates in northern Mexico and the country's eastern coastal areas.

The cartel, like other Mexican criminal organizations, has expanded into kidnappings and extortion rackets, targeting businesses.

Nuevo Leon and other parts of northeastern Mexico have been wracked in recent years by a territorial struggle between the Los Zetas and Gulf drug cartels that has resulted in hundreds of deaths.

Home to many of Mexico's industrial giants, Monterrey long seemed immune to the drug war that has claimed some 60,000 lives nationwide since December 2006, when President Felipe Calderon took office and militarized the struggle against the nation's well-funded drug cartels.

But the metropolis and its suburbs have been battered by a wave of drug-related violence since March 2010. EFE