Brazil police fire tear gas at Rousseff impeachment protesters (PHOTOS, VIDEO)

Police in Sao Paulo have used tear gas to disperse a crowd of supporters of suspended Brazilian President Dilma Rousseff on the day she is set to testify at her impeachment trial to deny accusations of hurting the economy with alleged budget manipulations.

READ MORE: 'Impeachment equal to political death penalty': Rousseff addresses Brazilian Senate ahead of trial

Thousands of the president’s supporters have taken to the streets across all major Brazilian cities, ahead of an impending Senate vote on permanently removing the country’s first female leader from office. The body temporarily suspended President Rousseff's powers for up to six months in May.

To protest her potential impeachment process thousands flocked to the streets in Brasilia, Sao Paulo, and Rio de Janeiro. In Sao Paulo, the violent scuffles with police began unfolding at around 7:00pm local time, when activists from the Frente Povo Sem Medo (people without fear) movement decided to continue their march which took a direction that had not approved by the security forces.

After the official rally ended, several dozen people remained on Paulista Avenue next to Sao Paulo Art Museum (MASP). Cordoned by the military police, some protesters tried to pierce through the police lines forcing officers to use tear gas and rubber bullets to disperse the group, which retaliated by launching petrol bombs at police.

Refusing to obey police orders to quietly disperse, the protesters blocked the street with burning tires and trash, Globo reported. As the disturbance continued, at around 8:00pm local time, trucks with military police entered the avenue to use water cannons on the barricades erected by protesters. The demonstrators responded by pelting law enforcement with more Molotov cocktails.

Police were forced to move in behind the make-shift barricades to deploy tear gas to disperse the remaining crowd by 8:30pm. According to organizers, the event in Sao Paulo attracted more than 20,000 people.

In Brasilia, a protest against the impeachment gathered some 1,500 people, according to police estimates. Activists carried flags, banners and posters with messages of support for Dilma Rousseff and against the government of the interim president, Michel Temer.

Rousseff supporters rallied outside the National Congress building as she was questioned on the Senate floor during her impeachment trial.

Taking the stand on Monday at her impeachment trial in the Senate, Rousseff testified that she was innocent of the charges brought against her, namely manipulating the federal budget to cover the extent of Brazil’s economic problems.

Senators’ vote on whether to convict Rousseff, who was suspended from office in May, is expected as early as Tuesday. The lawmakers need two-thirds of the 81-member Senate, or 54 votes, to permanently oust her from office.