Spain said it is tightening its borders in anticipation of violent anti-austerity protests at the upcoming European Central Bank summit in Barcelona.

The Madrid government announced Tuesday it will suspend the EU's Schengen Agreement visa-free protocol beginning Saturday and require border checks for anyone entering the country.

The measures will be in effect through May 4, one day after the ECB summit, which is coming amid a popular backlash against deep austerity measures proposed by Spanish Prime Minister Mariano Rajoy and his conservative government.

The Schengen Protocol, established in 1985, allows for the free travel between the 25 EU members states that have signed the agreement. But it also contains a provision to suspend the rules for up to 30 days in cases of a "serious threat to public order or internal security."

That clause was invoked by Catalonia's minister for home affairs, Felip Puig, who cited police reports indicating the possibility of foreign nationals going to Barcelona to provoke violent protests, the Catalan News Agency reported.

Puig asserted in the security request that local police are seeking to keep out "anti-system violent" foreigners who want to enter the country -- a request he said is supported by police reports evaluating the risks to Spain.

Also, some 6,500 officers are to be deployed in Barcelona ahead of the summit. Officials said about 4,500 Catalan police officers and 2,000 members of the national police force will collaborate with the effort.

Rajoy said land borders with France were to be reinforced at La Jonquera, Port Bou, Puigcerda, Camprodon, Les and Canfranc, with additional forces deployed at the Girona and Barcelona airports.

Police say the ECB summit will likely be targeted by a wide spectrum of foreign and domestic protesters who oppose the tough austerity measures sought by debt-laden European governments, which are under pressure by lenders to shore up their finances.

In Spain, hundreds of thousands of protesters took to the streets last month, joining general strikers in denouncing changes to work rules that weakened collective bargaining rights.

Several violent clashes were reported in Barcelona.

The conservative government, elected in November, Tuesday unveiled its new budget, which seeks to slash spending by $36 billion and reduce the deficit from 8.5 percent to 5.3 percent of gross domestic product in a single year.

It was presented as the country officially tipped into a recession and the government insisted tough measures must be taken to assure international creditors, Euronews reported.

"The situation is difficult, very complicated and the government is aware of that, so that is why we are taking those decisions to overcome this grave situation," Rajoy said.

Under his new budget, pensioners will have to start paying 10 percent of once-free prescription drugs, while working people who once paid 40 percent will now have to cover 60 percent of their drug costs.

Students will also face higher university fees while teachers will be made to work longer hours with larger class sizes under the budget.

Spain has mostly avoided the large-scale protests seen this year in Greece, where harsh austerity moves triggered weeks of violent unrest. Analysts note, however, that unemployment is predicted to reach 24 percent with few economic stimulus measures likely coming, Euronews said.