A demonstrator chants slogans in a loudspeaker during a march dubbed "the Marches for Dignity 22-M" to protest against austerity in Madrid on Saturday. Eight "columns" of demonstrators, in an attempt to highlight the plight of struggling Spaniards, converged on Madrid on Saturday for a mass protest. Photo: AFP

Violence flared as tens of thousands of people descended on Madrid on Saturday, some having trekked from the furthest corners of Spain, at the end of a month-long "march for dignity" against the dire state of the economy.

What had been a day of largely peaceful demonstration took a violent turn in the late evening, as dozens of youths smashed the windows of a bank, set bins on fire and threw projectiles at police.

Police responded by firing rubber bullets and charging to disperse the protesters. Seventeen people were arrested and emergency services said 30 police and 41 protesters were wounded.

Earlier in the day, eight columns had converged on the capital - carrying flags from Andalucia in the south, Catalonia in the east, or the Asturias in the northwest - at the culmination of nearly a month of walking for some of the protesters.

"Rise! Rise! We will fight!" chanted one group gathered at Atocha station before heading down the broad avenues of Madrid's city center.

The "march for dignity" comes after two years of bruising austerity measures, forced on Spain as part of a 40 billion euro ($55 billion) international bailout after a huge housing bubble almost destroyed its banking system.

Austerity has left Spain in a prolonged economic funk, with more than 26 percent of the population - and half of under-25s - out of work.

Meanwhile, say protesters, the corrupt collusion between officials and bankers that caused the crisis has gone largely unpunished.

"No to unemployment, no to exile, no to insecurity. March, march, march for dignity," the crowds chanted.

"It will be a tide of citizens that will restore the dignity of the capital," promised Diego Canamero, spokesman of the Andalusian Workers' Union, one of 300 groups taking part.

"Either the government responds to our demands or it must pack its bags," he said.

The organizers hired hundreds of buses and at least four trains to transport protesters on Saturday, while the government deployed around 1,700 police.

AFP