The so-called “marcha negra”, or “black march” has mobilized about 180 hard-hatted Spanish miners from three coal mining provinces in outcry over government subsidy cuts to one of Europe’s last hotbeds of coal activity.

The relatively peaceful march builds on a month of strike activities but has been largely overshadowed by intermittent clashes with paramilitary police, such as yesterday’s barricading of a highway between the coal-rich provinces of Asturias and Leon.

Coal miners in makeshift masks to protect their anonymity reportedly blocked motorway AP-66 near the northern capital of Oviedo with burning debris until police displaced the conflict to a nearby village where further violence ensued.

Reuters said clashes between miners and the Guardia Civil resulted in the use of bottles, exploding home-made rockets, slingshots and rubber bullets.

The strike, originally planned as a four-day manifestation, has been recast as an “indefinite” movement by the country’s two largest trade unions.

Victor Fernandez is a spokesman for the Union General de Trabajadores which is taking part in the march on Madrid.

"If they can afford all those billions to bail out the banks, why can’t they find 300 million euro ($US376 million) for this national industry,” he told Platts.

Spain has already asked the European Union for up to €100 billion ($US125 billion) in aid for its banks.

Yesterday, Reuters said the country’s short-term borrowing costs nearly tripled at auction, underlining the precarious nature of its finances.

Cuts to the country’s coal industry are part of widespread austerity measures which Prime Minister Mariano Rajoy said would allow the country to emerge from Europe’s financial crisis.

Unemployment in the country is the highest in the eurozone at more than 24%.

Spain’s total coal resource as of 2010 was about 4.5 billion tonnes.