More than 1,000 police and soldiers brace for military-style assault on drug traffickers in four of the city’s favelas.

More than 1,000 police and soldiers are preparing to raid four of Rio de Janeiro’s most dangerous slums, or favelas, in a bid to root out drug traffickers.

Crackdowns on narcotics have become common in Rio, where city officials say security forces have removed armed drug traffickers from 28 favelas in recent years.

Critics say the military style invasions are too heavy-handed, and simply push the drug gangs to other parts of the city.

Al Jazeera’s Gabriel Elizondo reports on Rio de Janeiro.