Some 500 soldiers, some in armored vehicles, swept into Rio de Janeiro's Rocinha favela Tuesday to support a police raid after gun fights broke out between rival drug gangs.

Officials said the operation was focused on the outskirts of Rocinha, especially in the forested area that borders the upscale Gavea neighborhood where authorities say some of the drug traffickers are hiding.

Rio police, supported by the Brazilian military, "searched the jungle area of the Rocinha community," the state security office wrote on Twitter.

The military is offering "technical support" for an operation "to find hidden material that was already detected" by intelligence agents, Colonel Roberto Itamar told Globo TV news.

"We're searching for weapons, ammunition, explosives, all that material that's being used" by the rival gangs struggling to control the favela, Itamar said.

Tuesday's operation comes after Defense Minister Raul Jungmann sent 950 troops to Rocinha in September to back police after heavily armed drug traffickers sprayed bullets and rampaged through the teeming cluster of small houses on hillsides overlooking wealthy western Rio.

The troops left Rocinha -- Brazil's most populous favela -- on September 29, when officials declared the situation "stabilized."

Violence is common in favelas, where drug gangs control much of the territory and police are forced to remain on permanent alert.

Nowhere else in Brazil do rich and poor live so close together as in Rio, whose poorest neighborhoods are part of the fabric of the city and not kept at arm's length in the outskirts, as in Brasilia or Sao Paolo.

Around a quarter of Rio's population of around 6.5 million live in favelas.

Source: AFP