Tens of thousands of people demonstrated Wednesday in downtown Madrid in support of coal miners and against a sharp reduction in subsidies for Spain's mining sector, an initially peaceful protest that escalated into clashes with police that left 76 injured.

The so-called "black march" also turned into a protest against new austerity measures announced Wednesday by Prime Minister Mariano Rajoy, including cuts in unemployment benefits and a hike in sales taxes.

More than 200 coal miners who arrived in the capital Tuesday after setting out on foot from northern Spain nearly three weeks ago marched at the head of the demonstration.

Police arrested seven people outside the offices of the Industry Ministry, the end point of the march, while 76 people - including 33 cops - needed treatment for bruises, sprains and other minor injuries.

Clashes between police and coal miners protesting cuts of up to 63 percent in subsidies for their sector this year also erupted in another part of the route, near the Real Madrid soccer club's Santiago Bernabeu Stadium.

While the march of more than 500,000 people - according to organizers - was unfolding on the streets of the Spanish capital, Rajoy was announcing the latest austerity package at the lower house of Parliament.

In remarks at the conclusion of the march, leaders of Spain's main labor unions, Comisiones Obreras and the UGT, called for a wider mobilization of workers later this month to protest the new fiscal measures.

The demonstrators arrived at the headquarters of the Industry Ministry after marching for more than two hours.

Chanting slogans such as "The Enemy is Within" and "We're Not Terrorists, We're Miners," the protesters concentrated around the metal fence that serves as the ministry's security perimeter.

After most of the demonstrators had arrived, they pushed up against the fence and knocked it over and began pelting police with firecrackers and rocks.

The cops responded by beating back the protesters with clubs and firing rubber bullets.

Rajoy announced the new austerity measures - the fourth such package of his seven-month-old administration - in a bid to achieve 65 billion euros ($80 billion) in savings and meet a European Union-mandated budget deficit target.

The new measures are part of Spain's obligations to the European Union in exchange for a bank bailout and additional time to bring its national budget deficit in line with the bloc's mandates, Rajoy said, adding they also are justified because of the country's "gloomy" economic prospects for 2013.

Spain must bring its deficit down to less than 3 percent of gross domestic product in 2014, compared with 8.9 percent of GDP in 2011.

Thanks to an agreement reached with Spain's euro-zone partners, the Iberian nation's budget deficit target for this year has been set at 6.3 percent of GDP as opposed to an earlier target of 5.3 percent, while the goal for 2013 is a deficit of no more than 4.5 percent of GDP.

The austerity announcement came in the wake of renewed pressure on Spain's sovereign bond yields and just 24 hours after the euro-zone countries gave the green light to an agreement to loan the Iberian nation up to 100 billion euros ($122.5 billion) to shore up its ailing banking sector.

The measures due to take effect immediately include an increase in the value-added tax from 18 percent to 21 percent, although the sales tax for basic goods such as bread and medicine will remain at 4 percent.

Other moves involve reducing the unemployment pay people receive following six months of joblessness. Those out of work, however, will remain eligible for government benefits over a two-year period.

Rajoy referred during his speech to the serious unemployment crisis in Spain, where the jobless rate exceeds 50 percent among young people and 24.6 percent overall.

He also said Spain faces an urgent situation in which "we need them to lend us money to pay even things like unemployment benefits, the salaries of government employees, health, education."

And because Spain's borrowing costs are very high - more than 6 percent for its benchmark 10-year bond in debt auctions - "we're trapped in an unsustainable, vicious cycle that we need to escape from as quickly as possible," said Rajoy, who insists that the first step to economic recovery for Spain is getting its financial house in order.

The Iberian nation's economy has been battered in recent years by the global recession and the collapse of a massive real-estate bubble, which has left many of its banks saddled with toxic property assets. EFE