President Dilma Rousseff on Monday hit out at alleged Canadian spying on Brazil's Mining and Energy Ministry, demanding that the United States and its allies stop such practices.

She said on her Twitter account that revelations aired by Globo television Sunday that the energy ministry was targeted by Canadian intelligence "confirm the economic and strategic motives" behind the electronic espionage.

Canada spied on communications at Brazil's Mining and Energy Ministry, according to Canadian intelligence documents revealed late Sunday by Globo television.

Documents leaked by former U.S. intelligence contractor Edward Snowden, purportedly from the Canadian Security Intelligence Service, show a detailed outline of the Brazilian ministry's communications including phone calls, email and Internet traffic.

After almost six years of waiting, Brazil's energy giant Petrobras is readying a major auction this month of its deep-water "pre-salt" oil reserves, despite fears of excessive state meddling.

The October 21 Libra oil field auction in Rio de Janeiro -- which experts say could put 12 billion barrels of oil up for grabs -- has been highly anticipated as the start of the sell-off of the total deep-water reserves.

Brazil, Latin America's economic behemoth, is in dire need of structural reforms and reduced government bloat to fuel sustainable growth, analysts say.

This, they add, will not happen overnight and will take massive political will.

Brazilian scientists will next month begin clinical tests on humans of a new vaccine against dengue fever, a leading Sao Paulo-based biomedical research institute said Thursday.

The vaccine is being developed to combat the four closely related strains of dengue viruses that have been identified around the world, the Butantan institute said in a statement.

The release of a huge cloud of chemical smoke from a fertilizer warehouse fire caused jitters in a southern Brazilian town Thursday amid fears that it might be toxic.

The blaze erupted late Tuesday at a fertilizer depot in the town of Sao Francisco do Sul, causing panic and forcing the evacuation of 800 people.

Brazilian President Dilma Rousseff launched a blistering attack on the United States Tuesday at the United Nations over America's widespread spying on her country.

"The argument that illegal interception of information is allegedly intended to protect nations against terrorism is untenable," Rousseff told the opening of the U.N. General Assembly.

Argentina and Brazil are planning a coordinated response to U.S. spying in Latin America, officials said Thursday.

The two countries' foreign ministers met in Buenos Aires to discuss U.S. cyber-spying on Brazil and other Latin American allies, amid a diplomatic row over the practice.

An ivory toothbrush thought to have belonged to Brazil's Emperor Pedro II and a minty toothpaste made by a European chemist for the Portuguese queen are among more than 200,000 pieces dating from the 17th through 19th centuries that archeologists have unearthed from a site in Rio de Janeiro being used for an extension the city's subway lines.

A team of more than two dozen archeologists, historians and others began excavating the plot in northern Rio last March. The plot, once the site of a slaughterhouse, is near the former imperial palace and thought to have once been used as a landfill by the imperial family and others, team members said Wednesday.

A small group of Brazilian youths got naked outside Congress Wednesday to demand an end to secret voting in the legislature.

"Democracy is not conducted with secret votes, so we need an open vote," said Michael Mohallem, one of the organizers of the protest by several dozen.