Massive protests sweep Brazil, calling for President Rousseff's resignation

Unionists and Workers Party (PT) members take part in a demonstration against hatred and intolerance and supporting democracy in front of the Lula Institute's offices, in Sao Paulo, Brazil on Aug. 16, 2015. 

Protesters took to the streets across Brazil today, ratcheting up pressure on President Dilma Rousseff's administration.

Sunday was the third day of nationwide anti-government protests in Brazil this year, following large-scale demonstrations in March and April.

Protest organizers issued a variety of demands, ranging from Rousseff's impeachment to a return to military dictatorship, according to AP. An end to corruption was also high on the grievance list, amid a widening probe into the state-run Petrobras oil company.

Rousseff's popularity ratings have fallen to the lowest on record for any Brazilian president, amid the corruption investigation into Petrobas and general economic decline. AP reports a poll earlier this month showed only 8 percent of those surveyed considered Brazil's government to be "great" or "good." By contrast, 71 percent said the government is a "failure." 

Protests were underway Sunday in the capital Brasilia, where the Washington Post said 25,000 marchers headed toward Congress carrying a banner that read "Impeachment Now."

Thousands streamed onto Copacabana Beach in Rio de Janeiro, and AFP reported marches in the country's financial center of Sao Paulo. 

Smaller demonstrations were also underway in the Amazonian city of Belem and the central city of Belo Horizonte. More than 200 demonstrations are expected in total around the country.

Analysts say Sunday's protests will serve as a barometer for the overall protest movement in Brazil. 

"While calls for Rousseff to step down will be the headline of Sunday's demonstrations," the Eurasia Group, a political risk consulting firm, said in a research note, according to AP. "The greater risk for the government would be if massive protests become frequent and if they are followed by movements from organized labor,"