Brazil's President Dilma Rousseff has held an emergency cabinet meeting to discuss the country's most widespread unrest in two decades.
Protests began more than a week ago over transport fare rises, but they are now also directed at corruption and the cost of next year's football World Cup.
More than a million people are reported to have taken part in demonstrations on Thursday in about 100 cities.
One man died when a car drove through a barricade in Sao Paulo state.
A woman died of a heart attack after collapsing during demonstrations in the northern city of Belem.