Protesters demonstrating in support of teachers receiving better pay in the Brazilian cities of Rio de Janeiro and Sao Paulo have clashed with police.
The centre of Rio was packed with more than 10,000 people marching peacefully.
But as it got dark, some protesters threw firebombs at public buildings and riot police responded with tear gas, reports the BBC.
A similar protest in Sao Paulo also ended in violent confrontation with police after many banks were ransacked by hooded protesters.
The latest demonstration took place over several hours and was peaceful at first.
But once night fell, violent incidents broke out as at least 20 "black bloc" anarchists smashed a City Hall gate while others broke into banks and tried to break break into ATMs. Some banks were set alight, the BBC reports.
Demonstrators also torched a bus on busy Rio Branco Avenue, and took furniture out of banks to use in barricades as the stand-off off with police continued.