Mexico boosts security on northeast border after cartel boss arrest MEXICO CITY (Reuters) - Mexican authorities have increased security along the country's northeastern border with the United States after arresting the suspected leader of the Gulf Cartel, one of the oldest drug trafficking groups in Mexico, a spokesman said on Sunday. The Mexican army on Saturday captured Mario Ramirez Trevino in Reynosa in Tamaulipas state, across the border from McAllen, Texas, Interior Ministry spokesman Eduardo Sanchez said at a press conference without providing further details. Ramirez was also wanted by the United States for trafficking cocaine and marijuana through the border crossings at Reynosa and McAllen and Matamoros and Brownsville, Texas. He is suspected of ordering attacks that killed police and security forces in the area, the spokesman said. "The government has reinforced the security strategy with the aim of neutralizing any eventual actions by other criminal organizations with a presence in this region," Sanchez said, appearing to refer to the brutal Zetas gang. The Zetas, which began by providing protection to the Gulf Cartel's operations, broke with the organization in 2010, unleashing a wave of violence in Tamaulipas and neighboring Nuevo Leon state. The Zetas also operate in Tamaulipas, but their main base is in Nuevo Laredo, where much of Mexico's legitimate business crosses into the United States. Sanchez spoke of organizations "that could seek to reposition and expand their area of influence, which could possibly increase levels of violence in the region." In July, the government arrested Miguel "Z-40" Trevino Morales, leader of the Zetas, in the first big blow to organized crime since President Enrique Pena Nieto took office in December. But in spite of the arrests, the violence has not let up and more than 6,000 people have died since December in clashes between cartels and security forces. About 70,000 people died while President Felipe Calderon was in power between 2006 and 2012. Calderon began the army-led campaign against the cartels. Reporting by Anahi Rama; Editing by Paul Simao