On Monday, Colombian authorities began exhuming what is considered the world's largest urban mass grave. The grave, said to contain over 300 bodies, is located outside the city of Medellin. The bodies are believed to correspond to victims of military operations launched during President Alvaro Uribe's administration and could be linked to the false positives scandal, in which over 4,300 innocent civilians were killed by the army and dressed up as guerrillas. teleSUR