By Dialogo February 14, 2012 On February 9, a group of 73 undocumented Central American immigrants, including 18 minors, was rescued from three buildings where they were being held in Mexico, near the border with the United States, the Mexican Secretariat of Defense announced. The immigrants were identified by the secretariat as “Central American nationals.” Four people who were responsible for guarding them were arrested and were to be turned over to the judicial authorities. AFP attempted to learn the nationality of the immigrants or details about those arrested, but the secretariat referred inquiries to the text of the statement, which indicated that the rescue operation “was executed in a coordinated way, simultaneously, and with surprise.” In 2010, also in Tamaulipas, the corpses of 72 undocumented migrants from countries such as El Salvador, Honduras, Brazil and Ecuador, were found murdered after refusing to work for the Los Zetas cartel, according to testimony by a survivor. According to Mexican Government figures, around 140,000 immigrants, the majority of them from Central America, cross the country annually en route to the United States, although non-governmental organizations raise that figure to around 400,000. In Mexico, undocumented migrants are targets of extortion, robbery, abuse, and murder at the hands of organized crime. In some cases, official complicity has been reported.