Colombia used to be the world's top producer of cocaine. But because of increased government efforts to curb the illegal trade, drug gangs can now only export half the amount they used to.

The war on drugs has reportedly helped reduce murder rates across the country.

But in Cali, which was once the centre of Colombia's infamous drug cartels, many people say increased rivalry between gangs has once again made it one of the country's most dangerous cities. 

Teresa Bo reports from Cali.