The Brazilian military has deployed thousands of troops to the country's western border to combat the smuggling of drugs and weapons through Bolivia, Paraguay and Peru.

Brazil insists that the operation - involving the country's army, navy and air force - is meant to target illegal activities and exert more control over its vast borders.

However, some officials in neighbouring countries have been critical of the operation - saying it is provocative military action that hampers cross-border trade and commerce.

Al Jazeera's Gabriel Elizondo reports from Sao Paulo.