A crackdown on drug smugglers has resulted in a dramatic jump in the use of sophisticated tunnels under the Mexico-U.S. border, Reuters reports.
Reuters reports that authorities discovered more than 100 tunnels during President Felipe Calderon’s five years in office. That number is double the ones found over the previous 15 years.
Reuters reports that the cartels have been perfecting the way the tunnels have been built.
The more sophisticated tunnels have hydraulically controlled steel doors, elevato and elecric rail tracks and are built with expensive drilling equipment, Reuters reported.
“It’s evident that those who constructed these tunnels are specialists, not only for the size but also because it requires study of the soil to prevent it from caving in,” General Gilberto Landeros, a Mexican army commander, during the recent discovery of a Tijuana tunnel told Reuters. “The machinery they use for construction is really sophisticated.”