Brazil's security forces have seized control of several slums here in a new bid to crack down on drug trafficking ahead of the 2014 World Cup and the 2016 Summer Olympic Games.

More than 1,400 members of local military and civil police backed by 17 vehicles and a helicopter charged into the complex narrow streets at dawn Sunday in Caju, a shantytown district near Rio de Janeiro's international airport and seaport.

The 25-minute operation did not meet any resistance from the drug traffickers, as they had abandoned the slums weeks ago after the occupation was announced.

Flags of Brazil and Rio de Janeiro were hoisted to signal restoration of government control over the zone, which had been controlled by heavily armed drug traffickers for years.

"We were well prepared to face any dangerous situations and the goal is to minimize the risk for the population," Capt. Alexandre Lima Ramos told the press.

Twelve people were arrested and a large amount of weaponry and drugs were seized.

The Caju complex includes 13 slums, also called "favelas," accommodating more than 16,000 people.

The Brazilian government has launched several operations to take over Rio's slums, drive out drug traffickers and permanently deploy police at the favelas.

The operation in Caju is part of the government's new bid to fight organized crime and restore full control in Rio and its suburban regions ahead of the two major sport events.