Police clashed with striking subway workers in Sao Paulo yesterday as traffic chaos gripped the Brazilian mega-city less than a week before it hosts the soccer World Cup's opening match.
Police fired tear gas and swung batons to beat back the picketing strikers after commuters tried to enter a major metro station amid torrential rain that has added to the traffic misery.
The indefinite work stoppage, now in its second day, has raised fears of unrest when the country's business hub hosts next Thursday's game between Brazil and Croatia.
The clashes came as Brazil's national team prepared to play their last friendly against Serbia in Sao Paulo's Morumbi stadium, not the new Corinthians Arena, which has yet to be finished six days from the inaugural match.
The Sao Paulo metro is the main link to the Corinthians Arena, and the strike could force organisers to come up with last-minute alternative transport for tens of thousands of fans.
The traffic mayhem has stranded the 4.5 million passengers who use the subway system daily in the sprawling city, while bumper-to-bumper traffic stretched for up to 250km.
"I'm going to have to return home. I can't get to work like this. The metro is not going there and with this traffic, it's impossible to go by bus," said Pedro Henrique Rodrigues, who stood in a massive line of people waiting for buses.
Another strike by 75 per cent of Sao Paulo's traffic police increased transport problems.
The chaos in Sao Paulo is the sort of incident that the Brazilian authorities and the world football body Fifa want to avoid following the violent protests that marred last year's Confederations Cup, a World Cup dress rehearsal.
It was in Sao Paulo - a city of 20 million people - that mass protests erupted a year ago as citizens took to the streets to voice anger at rising public transport fares.
The unrest ballooned into nationwide demonstrations against the US$11 billion being spent on the World Cup, with more than one million people taking to the streets to demand that money instead be spent on hospitals and schools.
Amnesty International said the police response to the protests had been characterised by violence and abuses, and warned Brazil against cracking down on demonstrations during the World Cup.
On Thursday, frustrated commuters broke entrance gates at the station that serves Corinthians Arena.
After some of them jumped onto the tracks, system operators CPTM decided to open the station in a bid to calm the situation.
The protest movement has lost momentum since last June, but the transport chaos risks rekindling anger as the opening ceremony nears.