Protesters snarled rush hour traffic and closed down the metro in Brazil's economic center Sao Paulo on Friday at the start of a nationwide strike called by unions opposing austerity reforms.
Police used tear gas to clear highways of protesters. But bus services, the metro and trains all stopped working, bringing the country's biggest city to a standstill.
In Rio de Janeiro, protesters lit fires on a major bridge, disrupting commuter traffic. Many banks were shut.
However, the city appeared to be less affected, with private businesses such as restaurants, cafes and shops opening normally.
In Belo Horizonte, another major city, the metro was also completely closed down, CBN radio reported.
Unions and leftwing organizations called for a general strike to oppose center right President Michel Temer's push for a sharp reduction in pension benefits and other austerity reforms.
The strike appeared to be having greatest effect in heavily unionized parts of the economy, including transportation, the post office and some hospital staff.
Despite reports of delayed and cancelled flights at some airports, a spokesman for the National Civil Aviation Agency told AFP that "operations at the airports are functioning normally."
Temer has said that without severe fiscal discipline and belt tightening, Latin America's biggest economy will not be able to exit a two-year recession.
The most controversial measure is to raise the retirement age to 65 for men and 62 for women, up from 60 and 55 at present.
The government is also pushing for a liberalization of labor laws and has succeeded in getting Congress to pass a 20-year spending freeze.
The struggle over austerity comes against a backdrop of ever worsening conditions for ordinary Brazilians, even if government officials say the economy is slowly turning the corner.
The statistics office on Friday said unemployment had hit yet another new record at 13.7 percent for the last quarter, up from 13.2 percent, with 14 million people out of work.
Brazil's economy shrank 3.8 percent in 2015 and is expected to have contracted a further 3.5 percent in 2016, the most painful recession in a century.