Tens of thousands of people marched in the Spanish capital Saturday to demand a referendum on austerity measures enacted by Prime Minister Mariano Rajoy's administration.

Eight marches drawing thousands of people from different parts of the country converged on Madrid's downtown Plaza de Colon, where those protesters were joined by teachers, health and social workers and other public-sector employees.

According to protest organizers, some 2,000 chartered buses transported people to the capital to protest against the Spanish government's budget cuts and tax increases.

These latest anti-austerity marches - organized by the Social Summit, which comprises 150 grassroots organizations and Spain's biggest labor unions - were held under the banner "Let's Go! They want to ruin the country. We have to stop it!"

Some 65,000 people took part in the demonstrations, while a total of 507 buses brought people to the capital from other cities and towns, the national government's Madrid delegation said.

In speeches at the close of the march, the heads of Spain's UGT and CCOO labor federations, Candido Mendez and Ignacio Fernandez Toxo, urged Rajoy to pay heed to citizens' rejection of his budget cuts and said he holds the key to avoiding another general strike.

Shortly after taking office last December, the conservative premier overhauled Spain's labor law to make it easier for firms to hire and fire workers, a measure that triggered a 24-hour general strike in late March.

His government also has opted for a series of austerity measures, including increasing the value-added tax and reducing unemployment benefits, to bring Spain's budget deficit into line with European Union mandates.

Those moves have been widely unpopular in a country where the unemployment rate stands at nearly 25 percent and more than 50 percent among young people.

The Social Summit's declaration demands that the Spanish government hold a plebiscite on a sovereign bailout that the unions say the government is negotiating with the European Union.

The euro zone already has approved a 100-billion-euro ($131.2 billion) rescue of Spain's troubled banks

Spanish Economy Minister Luis de Guindos, for his part, said Friday that the Rajoy government is aware that it is asking society to make sacrifices but that they are "unavoidable" in putting the country on a path to recovery.

The protests unfolded peacefully, although four people associated with the May 15th Movement were detained for refusing to identify themselves and at least 24 people were treated for dizziness, fainting fits or falls.

At the close of the marches, several people tried to make their way to the headquarters of the ruling conservative Popular Party but were impeded by a large police contingent.

The protests were backed by the main opposition Socialist party and the United Left party, while numerous celebrities including singers Victor Manuel and Ana Belen, actors Pilar Bardem and Alvaro de Luna and film director Benito Zambrano joined the demonstrations.

Spain'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 banks saddled with toxic property assets.

The Iberian nation is in recession for the second time in three years.

Numerous businesses have failed amid the slump and tens of thousands of families have been evicted from their homes after falling behind on their mortgages. EFE