At least eight people were killed and 25 injured Tuesday when a commercial building under construction collapsed in Sao Paulo, officials said.

Rescuers said they did not know how many people might be trapped in the rubble. Search efforts continued through the night.

At least six people were killed and 24 injured Tuesday when a commercial building under construction collapsed in eastern Sao Paulo, officials said.

"So far we have six people dead and 22 people were rescued alive," a police spokeswoman told Agence France Presse, denying press reports of a seventh fatality.

The Bank of Brazil said Thursday it is ready to intervene heavily on currency markets from Friday, making available $55 billion to prop up the sagging real.

The central bank said it will engage in so called swap operations: it will offer dollars in the futures market, with a pledge to buy them back in a determined time frame no matter what they are worth.

Colombia on Wednesday more than doubled the size of a huge nature reserve as it fights to protect the Amazon from deforestation.

Environment Minister Juan Gabriel Uribe said deforestation of the Colombian Amazon is a worrisome problem, mainly because of land being cleared for growing coca leaves, logging, illegal mining and agriculture.

Deforestation in the Brazilian Amazon is on the rise sharply, sparking alarm over the future of the world's biggest rainforest.

Between June and last August, Imazon, the first independent monitoring system for the area, detected a 100 percent surge in the clearing of land.

The Brazilian government's popularity has started recovering after a steep fall following massive street protests over corruption and living standards, says a poll out Saturday.

The Datafolha survey, published by the daily Folha de Sao Paulo, put the approval rating at 36 percent this week, up from 30 percent in late June when it dropped 35 percentage points in the wake of the nationwide social turmoil.

An auction to privatize airports in Rio and Belo Horizonte, two host cities for the 2014 World Cup, will be held on October 31, Brazilian authorities said Friday.

Presidential chief of staff Gleisi Hoffmann announced the date for the auction to sell concessions to run

Brazil-based Guardian reporter Glenn Greenwald said Tuesday that he had received nearly 20,000 secret U.S. government documents from intelligence leaker Edward Snowden.

Greenwald, an American who was among the first to release details of Washington's vast electronic surveillance program, gave no details of the content of the files as he testified before the Brazilian Senate´s foreign relations committee.

The statutes of the new development bank planned by the BRICS group of five emerging powers could be ready next year, Brazil's foreign minister said here Tuesday.

"We made good progress during the last meeting in Durban and the expectation is that in the 2014 meeting in Brazil, enough progress has been made to conclude the statutes of the bank," Antonio Patriota told reporters.

Brazilian riot police fired tear gas, stun grenades and rubber bullets to disperse extremist protesters who ransacked bank branches, shops and a car dealership in central Sao Paulo.

A police spokesman told Agence France Presse that a total of 20 people were arrested during the clashes, which followed a peaceful march by 300 demonstrators against Sao Paulo state Governor Geraldo Alckmin.