Students and teachers from hundreds of universities and colleges across Brazil began a nationwide demonstration on Wednesday in "defense of education" following a raft of budget cuts announced by President Jair Bolsonaro's government.
Classes were suspended in numerous establishments as demonstrations took place in 17 of Brazil's 27 states, local media said, with particularly large ones in major cities like Sao Paulo, Rio de Janeiro, Brasilia and Belo Horizonte.
The biggest demonstrations are planned for the end of the day, though.
In the capital Brasilia, federal troops were deployed in front of the ministry of education in case of trouble.
The protest movement was sparked by Education Minister Abraham Weintraub recently slashing federal university subsidies by 30%.
Several chief education officers claimed the budget cuts would compromise the ability of federal universities to function, and threatened to paralyse them.
Then the sudden suspension of the payment of masters and doctorate scholarships in the sciences and human sciences last week threw oil on the fire.
"Secondary school pupils, university students, researchers, teachers and other education employees will take to the streets in every state" to protest against the budget cuts, the National Student Union (UNE) had announced on Tuesday.
Despite the cuts affecting only federal institutions, the protest movement has been joined by many private universities such as Rio's Pontifical University which voted last week to join the nationwide demonstration.