Protests have been held across Brazil as thousands of workers take part in a general strike against a government proposal to reform public pensions.
The strike, the first since far-right President Jair Bolsonaro took office in January, has affected public transport, schools and banks.
Police used stun grenades on protesters in Rio de Janeiro. In several cities, roads were blocked with burning tyres.
Mr Bolsonaro says the controversial reform will restore public finances.
The plan includes raising the minimum retirement age to 65 for men and 62 for women and workers' contributions. Critics argue the changes, which have to be approved by both houses of Congress, would penalise the poorest.
The one-day protest called by unions - the second general strike in Brazil in two years - affected public transport in São Paulo, the country's largest city, where subway workers joined the strike.
Transport had also been affected in other major cities, including Salvador, Curitiba and Maceió and the capital, Brasília. Many schools, universities, banks and parts of the state-run oil company Petrobras were also not working.
In dozens of cities across the country, protesters - who are also against cuts to the education budget - held demonstrations and, in some, blocked streets and roads with burning tyres.
In the city of Niterói, near Rio, at least two people were injured when a car ran over a group of protesters blocking a street.
The government estimates the current plan for the reform will result in savings of $237bn (£188bn) over the next decade. The changes are seen as crucial to revive the country's economy, still struggling to recover from the 2015-2016 recession, the worst in more than a century.
Opponents say the poor would be the most affected, as they are more likely to start working at a young age and would now be required to work longer before being able to collect pension benefits.
Congress is expected to vote on the reform in the next few weeks, and the new rules would phase in over 12 to 14 years.
Speaking to journalists, Mr Bolsonaro said he was confident that Congress would approve the reform.
Later, he is expected to attend the opening ceremony of the Copa America football tournament in São Paulo, where a special plan has been implemented for fans to arrive at the Morumbi stadium.