RIO DE JANEIRO - Tens of thousands of Brazilians turned out for demonstrations Sundays to oppose leftist president Dilma Rousseff, a target of rising discontent amid a faltering economy and a massive corruption scandal at state oil giant Petrobras.

Protests were scheduled for throughout the day Sunday and so far included 20,000 demonstrators in the capital Brasilia, 15,000 on Copacabana beach in Rio de Janeiro and 4,000 in Salvador de Bahia, according to police estimates.

A main protest was set to begin mid-day in Sao Paulo, the country’s economic center and a stronghold of opposition to Rousseff.

Dressed in the yellow and green of Brazil’s flag, many protesters demanded the impeachment of Rousseff who has just begun her second term after reelection at the end of 2014.

In Rio de Janeiro, people waved Brazilian flags along the coastal Copacabana avenue behind a truck blaring slogans against Rousseff. “Out Dilma, out PT,” people chanted.

A few protesters even called for military intervention to end the Workers Party’s (PT) 12 years in power.

Rita Souza, a 50-year-old television producer, carried a banner reading: “Military intervention now.”

“I’m not asking for a coup, but a constitutional intervention to call new fair elections,” Souza told AFP.

Construction contractor Alessandro Braga, 37, attended the rally in Brasilia with his wife and son. “I support the departure of Dilma,” he said. “The biggest corruption scandals occurred during her administration and she said nothing.”

Dozens of political figures, including close allies of Rousseff, and former Petrobras executives are under investigation over a kickback and money laundering scheme that saw an estimated $3.8 billion creamed off inflated contracts over a decade at the state-owned oil producer.

No one has yet been convicted, but some of the alleged wrongdoing took place while Rousseff was chairman of the Petrobras board.

Twenty-two deputies, 13 senators and two governors have been implicated in the bribe-taking allegations. Rousseff is not being investigated.

Rousseff supporters rallied Friday in Brazil, following calls by unions and social movements close to the PT. Those rallies were attended by 148,000 people, according to organizers, and 32,000 people, according to police.

In addition to the corruption scandal at Petrobras, Rousseff is also facing rising inflation and a Brazilian economy that is on the brink of recession.

Government deficits have widened and the real has lost 30 percent of its value against the dollar in the last 12 months.

Rousseff has pledged to implement austerity measures to stem the government’s rising debt, a move criticized by some in her own party.