Along the Colombian Pacific coast bordering Ecuador, the Narino department has long been crucial for coca production and cocaine trafficking to the United States. This region has been a "cauldron of violence," disputed for decades by multiple armed groups, explains Elizabeth Dickinson from the International Crisis Group (ICG) to AFP, until the guerrilla dissident group Segunda Marquetalia imposed itself and established a local presence with the support of Mexican cartels. IMAGES AND SOUNDBITES