Hundreds of thousands of protesters took the the streets on Sunday in more than 150 Brazilian cities to demand the ouster of Dilma Rousseff, the country's recently re-elected president, the Associated Press reported.

The demonstrations followed popular outrage over a sprawling corruption scheme, which has led to a plunge in Rousseff's approval numbers; even before the rallies, the president's popularity had already been cut in half, compared to when she defeated a center-right challenger in October, the news service noted.

Some 210,000 people gathered in São Paulo, Brazil's financial center, a crowd larger than any seen during daily anti-government rallies in June 2013. Back then, protesters' demands were aimed at poor public services and perceived endemic political corruption; today, the focus is also on the embattled president herself, the AP noted.

"I love Brazil. I love my country. And I am tired of corruption," a demonstrator on the city's famous Avenida Paulista told CNN. "We are tired of corruption. It doesn't matter which political party you are from, we are tired of being robbed."

Another protester, 35-year-old André Menezes, bluntly demanded Rousseff's ouster, according to USA Today.

"We are here to express our indignation with the government-sponsored corruption and thieving, and to demand (Rousseff's) impeachment," he said. "She may have not been directly involved in the corruption at Petrobras, but she certainly knew about it, and for me that makes her just as guilty and justifies her ouster," he added.

Petrobras is at the center of what federal prosecutors have described as a kickback scheme in which at least $800 million were paid in bribes to politically appointed former executives at the oil company. In exchange, construction and engineering firms obtained inflated contracts from the state-run oil company, according to the AP.

The right-leaning groups who organized Sunday's protest have called for a new round on April 12, but most analysts expect Rousseff to remain in office.

"While the next few months will be very difficult, we still don't think the government is headed to a governability crisis or that Rousseff is likely to be impeached," the New York-based Eurasia Group political risk consulting firm wrote in a Monday note.