Barcelona police have sealed off a warehouse said to be stocking ballot boxes, as Spain seeks to obstruct a Catalan independence referendum. The Guàrdia Urbana force was obeying an order from prosecutors to prevent the Catalan vote being held on Sunday. About 16,000 school and university students marched through Barcelona demanding that the vote go ahead.
Spain is deploying thousands of extra police in the region. Madrid has ruled out talks on a vote it sees as illegal. Some 10 million ballot papers have been impounded, and websites informing Catalans about the referendum have been shut down.
Guàrdia Urbana sources told Catalan daily La Vanguardia on Thursday that police would stop anyone trying to move ballot boxes to another location from the Calle Perú warehouse.
Catalan President, Carles Puigdemont, has told Catalans on Twitter how they can find a polling station to cast their votes - by using a special app. Meanwhile, Barcelona Mayor Ada Colau appealed to the European Commission to mediate in the standoff between Catalonia and the Madrid government, in an opinion piece in The Guardian.
She also accused Madrid of having allowed the long-running Catalan sovereignty issue to escalate from an internal dispute to a European conflict.
Catalonia, a wealthy region of 7.5 million people in north-eastern Spain, has its own language and culture, and has a high degree of autonomy. But it is not recognized as a separate nation by the Spanish state.
Spain's secretary of state for security, José Antonio Nieto, said Catalans could hold a demonstration and celebrate on Sunday if they wished, but they cannot violate the law and we all have to try to avoid that.
The Catalan government's foreign affairs chief, Raúl Romeva, echoed Ms Colau's plea for the EU to exert pressure on Madrid. Speaking at the EU headquarters in Brussels, he said the Spanish government was undermining the EU's democratic values, enshrined in Article Two of the Lisbon Treaty.
What we have today in Spain is the serious damaging of democratic rights and structures, he said. We call on the EU institutions to take a stand… democracy is being eroded.
He also vowed that in the event of a Yes vote on Sunday, the Catalan parliament would declare independence 48 hours after publication of the results.
That appeared to contradict the position of President Puigdemont, who said a unilateral declaration of independence is not on the table - even if a majority voted Yes.
Spain has chartered three cruise ships to house up to 6,000 extra police officers in Barcelona and another port city, Tarragona. But Mr Puigdemont said it was impossible for Spain to seal off the region.
The Catalan police force - the Mossos d'Esquadra - is about 16,800 strong and has been ordered by Catalonia's chief prosecutor to help block the referendum preparations. But the Mossos have warned that public order could deteriorate if its officers are deployed to prevent people from voting.
Spain's paramilitary Guardia Civil force has beefed up its presence in Catalonia.