Brazilian security forces have taken control of a major Rio de Janeiro drug trafficker stronghold.

巴西安全部队已经控制了里约热内卢一个主要贩毒团伙的据点。

Some 2,600 police and troops, backed by armoured vehicles and helicopters, moved into the Alemao complex of slums early on Sunday.

Drug traffickers had been given an ultimatum¹（最后通牒） to surrender by sunset on Saturday or face an assault.

Exchanges of fire were heard but reports suggest that police were met with less resistance than expected.

Heavily-armed officers hoisted²（升起，举起） the Brazilian and police flags on the hilltop shanty-town of Alemao.

'We won'

Forces are now moving from house to house, searching the area for hundreds of alleged³ drug traffickers who police fear may be trying to escape through the sewage（污水，下水道） system.

Officers said that during their search of the area they had found the luxurious⁴ mansion⁵ of one an alleged drug dealer⁶, complete with roof-top swimming pool and its own armoury.

The three-storey house with a sauna（桑拿浴） and disco was empty when the officers arrived and much of the electronic equipment inside had already been destroyed, police said.

Large amounts of weapons, ammunition⁷（弹药，军火） and drugs were also seized.

The operation follows a week of clashes between security forces and suspected drug dealers⁸ in several slums in the Rio area, with drug gangs fighting back with gunfire and setting vehicles on fire. At least 45 people have been killed.

Brazilian authorities say it aims to make the city safer ahead of the World Cup in 2014 and Olympic Games in 2016.

But human rights activists⁹ have accused Brazil of being too heavy-handed in its approach.

Within hours of Sunday's operation, police said they had taken control of the favela（贫民区） .

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

"Now it is time to be patient. We've taken over the territory but it doesn't mean that we won't have confrontations¹⁰ with the gang members still inside.

"We have to be careful because they may be trying to set up traps for our men," he said.

Residents have been told to stay at home and there were still some reports of gunfire.