RIO DE JANEIRO (AP):

Police and soldiers charged into Rio's most dangerous slum at daybreak yesterday, seizing the bastion of the city's biggest drug gang in a battle to make the seaside metropolis safe for the Olympics and soccer's World Cup.

Black-clad officers poured into the Alemao slum complex amid heavy gunfire, with helicopters flying low overhead. But the officers encountered less resistance than expected and they declared victory two hours later, even if many gang members still remained inside.

A Brazilian flag was raised at the shanty town's highest point at midday.

It was the biggest victory yet in a two-year effort to drive drug gangs from their strongholds in the hundreds of shanty towns, many draped across the hills around Rio's beaches, a crusade driven in part by the need to make foreign visitors feel secure for the final matches of the 2014 World Cup and for the 2016 Olympics that are meant to be showpieces of Brazil's emergence as a growing world force.

Rio de Janeiro Governor Sergio Cabral said the campaign against gangs would go forward.

"We will continue to conquer more territories and give peace to our citizens and the foreign visitors who come here," he told Globo TV.

Officials have already imposed order on more than a dozen other former gang strongholds, even encouraging tourism along streets once echoing with gunfire.

The gangs, feeling threatened, reacted violently, mounting mass robberies of motorists on key highways, burning more than 100 buses and cars and shooting up police outposts.

The government counter-attacked with hundreds of soldiers and thousands of police in armoured vehicles, first driving the gangsters from the Vila Cruzeiro slum last Thursday, then neighbouring Alemao, their most ambitious target yet, 72 hours later.

Suspected drug traffickers dead

At least 36 people, mostly suspected drug traffickers, have died in the gang violence and resulting police raids in the past week.

Officials earlier warned that as many as 600 gang members were holed up in Alemao, a district of some 85,000 people, but by nightfall yesterday they had made only a handful of arrests, including a few of the slum's reputed top gang leaders.

Police said they think at least 200 gangsters remain hidden in the slum, and warned that sporadic shoot-outs were likely in the coming days.

At least one suspected trafficker was killed in the invasion and at least two people were injured.

"We won," said Mario Sergio Duarte, head of Rio state's military police. "We brought freedom to the residents of Alemao."