Hidden cells reveal Bolivia's dark past

"There is no beginning without an end, but you will pay me back," reads an engraving on the wall of a dark and humid room in the basement of a government building in Bolivia's administrative capital, La Paz.

Next to it, stains of blood drawing four fingertips seem like grim blemishes, not at all adornments. Bolivia is unearthing this dark part of its past.

The left-wing government of Evo Morales has recently discovered what his government calls"the horror chambers" - torture cells found by chance when contractors uncovered blocked off hallways in the basement of the Ministry of the Interior.

Those hallways led to cells where around 2,000 political prisoners were held and tortured during the 1971-1978 military rule under General Hugo Banzer.