Tens of thousands of people are joining marches across Barcelona in protest against the Spanish government’s actions over the region’s independence vote.

Separatist groups and unions had initially called for strikes to be held on Tuesday in support of Catalan leaders pushing ahead with a declaration of independence from Spain. But many non-separatists were also drawn to the streets following a crackdown on a referendum vote on Sunday.

The main national unions, CCOO and UGT, rejected the strike but told workers to join protests.

BarcelonaProtesters during a one-day strike in Barcelona (Bob Edme/AP)

In Barcelona’s Catalonia and University squares, a sea of demonstrators waved flags, most of them “esteladas,” embraced by those seeking secession, but there were also plenty of Spanish national flags.

Among many banners displayed, one read “Stop violence, #CataloniaIsComing” and another one wondered “Where are you Europe?”

One of the biggest groups concentrated around the Spanish national police headquarters in Barcelona, where protesters called them “occupying forces” and called for Prime Minister Mariano Rajoy to resign.

Earlier Barcelona’s football stars were among workers in Catalonia to down tools.

The club said none of its professional or youth teams were training and the club base was closed.

Girona’s team also did not train while Espanyol’s players underwent physical exercises behind closed doors.

Barcelona defender Gerard Pique, one of the most outspoken supporters of Catalonia, was harassed by fans on Monday when he reported to Spain’s national team training camp in Madrid ahead of upcoming World Cup qualifiers.

Several hundred Barcelona port workers held a demonstration outside the regional headquarters of Spain’s ruling Popular Party chanting slogans against government policies and the alleged brutality of police during Sunday’s polling day.

The port workers threw wads of unused ballot papers from the vote into the air in the protest outside the party’s office in Barcelona.

Gerard PiquePro-independence supporter and Barcelona defender Gerard Pique was harassed by Spain fans when he turned up for training with the national team in Madrid (Gian Ehrenzeller/Keystone via AP)

Regional police placed barriers outside the building to stop the crowd getting near the offices and the protest lasted more than an hour.

Madrid’s top official in Catalonia said he lamented the violence but blamed the regional separatist government for “exposing citizens to danger”.

Enric Millo said on Tuesday “nothing of this would have happened if the government wouldn’t have declared itself in rebellion, breaking the orders of the courts and lying and tricking people”.

He said Spain’s National Police and Civil Guard anti-riot squads broke into schools designated as polling stations when it was clear that the regional Mossos d’Esquadra police, controlled by the Catalan government, was not carrying out a judge’s orders to impede the voting.

He also accused the grassroots groups driving the independence bid, the National Catalan Assembly and Omnium Cultural, and pro-independence mayors of “plotting to break the law”.