Those walking São Paulo's streets today can still see the occasional spray-painted slogan from June 2013: "3.20 is theft!" or "It's not about the 20 cents."

They are reminders of the city's 20-cent rise in the cost of public transport, from R$3 to R$3.20 (at the time equivalent to a bump from US$1.33 to US$1.42), which sparked a wave of demonstrations across Brazil, when a series of small rallies organized by a group called Movimento Passe Livre (MPL), or the Free Fare Movement, initiated a national protest campaign involving a million Brazilians. The outpouring of dissent prompted a repeal of the fare increase within 22 days.

A year and a half later, the cost of a single journey by bus, train, or metro in São Paulo jumped this week from R$3 to R$3.50, and from R$4.65 to R$5.45 for a combination bus-and-rail ticket — the largest increase in five years at roughly 17 percent, and a bold move on the part of municipal authorities eager to get transport subsidies under control. São Paulo alone faces paying out over $700 million in subsidies this year without a fare increase. Fares have also risen in eight other Brazilian cities in the last month, including in Rio de Janeiro, where the R$3 fare rose to R$3.40.

In response, the MPL organized a mass demonstration this evening, which assembled downtown at São Paulo's Teatro Municipal, close to the Prefeitura (City Hall), before moving up to the city's expansive Avenida Paulista. The group's first major call to action since the June 2013 protests audaciously seeks an end to fares on public transport altogether.

Protest in downtown São Paulo today over transportation fare hikes. How will the police react? (Photo — Simon Romero (@viaSimonRomero)January 9, 2015

"We're not trying to repeat what happened in June 2013," MPL member Luíze Tavares told VICE News ahead of the protest. "This time, it's not about a 50-cent increase — it's about the R$3 as well."

In a development that some in the movement regarded as an attempt to placate or even co-opt the MPL, São Paulo Mayor Fernando Haddad announced in December the implementation of free travel for students, up to a limit of 48 trips per month, in place of a previous 50 percent discount. State Governor Geraldo Alckmin announced a similar initiative regarding travel by train or metro, which falls under state control.

The financial burden of the fare increase falls squarely on single-ticket users, a shift that critics revile as socially unfair.

The measures, expected to come into effect as classes start in February, will apply to all public school students and to university students on a means-tested basis, benefiting around a half-million people, according to Haddad and Alckmin. The elderly and some passengers with mobility problems already travel free on municipal public transport.

The MPL doesn't think this is enough.

"It's a victory only in the sense that it's a result of the mass movement's actions," Tavares said. "Being able to move around the city is a right, not only for students but for everyone…. This is a gratuity for low-income students, not the free pass we've been demanding."

"Free pass" is nevertheless the term being used by Mayor Haddad to refer to the new student travel concession — the "passe livre estudantil." He deployed the phrase in a recent interview with El País, in which he also applauded the freezing of prices for monthly, weekly, and daily passes as a boon for regular commuters, many of whom receive a travel allowance from their employers for use in paying for passes.

"The vast majority of employees will not be affected in any way by the increase," he said.

But the selective benefit means that the financial burden of the fare increase falls squarely on single-ticket users, a shift that critics revile as socially unfair. Such users include visitors to the city and those who use public transport occasionally, but also the system's poorest passengers: those without travel cards linked to jobs and without sufficient means to purchase them, and who tend to travel the farthest, commuting into the city from far-flung homes along the periphery.

For a passenger traveling just four times a week, paying each way for bus-and-rail journeys at R$1.60 more per day represents a painful increase in a country where the monthly minimum wage is currently R$724 (US$270).

Despite significantly reduced journey times on buses thanks to more than 180 miles of new bus lanes implemented since Haddad took office in 2013, many São Paulo workers daily endure hours-long journeys on packed, uncomfortable buses as a fact of life. An audit of municipal bus services carried out in 2014 by Ernst & Young on behalf of Sao Paulo's government determined that the city's municipal bus operators routinely dispatch only nine of the 10 services they are contracted to provide, in breach of their agreements with the city. According to Haddad, the companies prefer to pay fines for the neglected services rather than fulfill their obligations.

The contracts are up for negotiation this year, in a bidding process that has been postponed since 2013.

On MPL's Facebook event page, almost 50,000 people had confirmed their attendance by the start of this evening's scheduled demonstration. By 6 PM, around 3,000 protestors had gathered at the Teatro Municipal before marching toward Avenida Paulista, surrounded by a cordon of police.

More images of repression during police intervention in São Paulo. — ?•ynd?cal??•? (@syndicalisms)January 9, 2015

Police Major Larry de Almeida Saraiva had earlier remarked to the Folha de S. Paulo newspaper that officers were authorized to use rubber bullets in the course of today's demonstration, if necessary. Police have exercised that authorization amid scuffles this evening, firing rubber bullets as well as tear gas canisters and stun grenades at demonstrators. As the protest continues, police have confirmed 32 arrests.

Até o momento 32 detidos sendo encaminhados ao 78º D.P. — POLÍCIA MILITAR - SP (@PMESP)January 9, 2015