Brazilian cities went into partial shutdown on Friday as the country observed its first general strike in more than two decades.
Millions of workers, including public transport staff, bankers and teachers, have been urged to take part by trade unions and social groups.
Protesters are taking a stand against the president's proposed pension reforms.
President Michel Temer says the changes are needed to overcome a recession.
"It is going to be the biggest strike in the history of Brazil," said Paulo Pereira da Silva, the president of trade union group, Forca Sindical.
Demonstrations are taking place across the country, with organisers saying they would focus attention on disrupting cities rather than small towns and rural communities.
Participants are opposed to the government's pension overhaul, which will be voted on in Congress next week and which could set the minimum retirement age at 65 for men and 62 for women. Public sector workers have been able to retire at much earlier ages.
A congressional bill to weaken labour laws also progressed earlier in the week, and the country is experiencing an ever-unfolding corruption scandal, which has been linked to many top politicians, fuelling further public discontent.
Some protesters set up roadblocks in various cities, including Rio de Janeiro, Sao Paulo, Belo Horizonte and Brasilia.
The route to Sao Paulo's international airport was among those barricaded with burning tyres in the early hours of the morning.
Empty streets in Sao Paulo - BBC's Daniel Gallas
Polls suggest President Temer is very unpopular but up until today he had not yet faced a mass demonstration like Friday's general strike.
Many private and public schools are closed across the country. In Sao Paulo - the country's biggest city - most bus, metro and train services are not operating. There are few people on the streets here and it feels like a holiday.
The government says the current pension system is unsustainable and is dragging down the economy. Unions say the president wants Brazil's poor and unassisted to pay the price for the country's economic woes.
Whatever the turnout is for the protest, Mr Temer still looks fairly strong in Congress. Earlier this week he won a vote for his labour reforms with a wider margin than needed.
This has been the hallmark of his administration: a president who is very unpopular in the streets, but is able to get things done in Congress.
A spokesman for the Anglican Church in the coastal city of Recife, Dr Juanildo Burity, told the BBC that it would also be taking part in the strike.
"Officially the Church has taken a position that encourages its members to be part of this movement, because it understands the political situation," he said, citing concerns over living standards.
President Temer says capping pension benefits and raising the retirement age will fix the finances of the country, as it undergoes the worst recession in more than a century.
The president has said the austerity measures are needed to prevent a future crisis such as that suffered by Portugal, Spain or Greece.
The country has also been hit by rising unemployment.
Government statistics released on Friday say more than 14 million people are out of work.