RIO DE JANEIRO (AP) - Protesters are gathering in Brazil's two biggest cities and a dozen others, with authorities bracing for the possibility of violence.
In Rio de Janeiro, thousands of striking teachers are demanding better wages as they march in the city's center on Tuesday - the nation's teacher recognition day.
Last week, a teachers' protest ended with scenes of sharp violence as so-called Black Bloc anarchist groups battled police.
In Sao Paulo, protesters are marching to support the teachers in Rio. But there are other groups demonstrating in the nation's biggest city, including groups fighting for affordable housing.
The "Roofless" movement adherents tried to invade the Sao Paulo city council building, but were pushed back by police.