MADRID (AFP) - Spain's interior minister warned in an interview published Sunday there was a "real" risk that Catalan government's push for independence could degenerate into violence.
"A process of these characteristics, by its very nature, generates radicalism. And all radicalism, in and of itself, is negative," Jorge Fernandez Diaz told conservative daily newspaper ABC.
"Therefore, denying the possibility that this radicalisation, combined with frustration, could degenerate in violence is not a possibility that shouldn't be contemplated," he added.
"I think it is a real risk. We must be vigilant against it, especially of those who with their political initiatives are generating this radicalisation which will likely lead to frustration.
"The combination of radicalisation and frustration is very dangerous."
The head of the Catalan government, Artur Mas, has vowed to step up its secession drive after a symbolic independence referendum last Sunday.
The Catalan government said 2.3 million people in the region of 7.5 million turned out for the vote, which was stripped of legal force after court challenges from Madrid.
Of the 5.4 million voters aged over 16 who were authorised to vote, 1.86 million favoured independence, it said.
In one of the few incidents reported, police arrested five people for damaging ballot boxes and causing unspecified injuries after bursting into a polling station in the northern district of Girona.
Mas has hailed the ballot as a "total success" but Spanish Prime Minister Mariano Rajoy has dismissed it as a "deep failure" since "two out of three Catalans paid no attention".
Catalonia's nationalist government has said it will now push for an official referendum similar to the one held in Scotland in September and will seek international support to help persuade Madrid to allow it to go ahead.
Mas has said that if he fails to reach an agreement with Rajoy over a referendum, he could call early regional parliamentary elections that might serve as a plebiscite on independence.
Demands for independence in Catalonia have grown over recent years despite Madrid's resistance, fanned by the economic crisis.
Catalans complain that their region does not receive investments in proportion to the taxes it pays and that the central government meddles in its linguistic and education policy.