Catalonia's government said 90 percent of those who voted in an unauthorised independence referendum chose to split from Spain.
On a day marred by clashes between police and voters, 2.26 million people took part in the referendum, regional government spokesman Jordi Turull said. That represents a turnout of 42.3 percent of Catalonia's 5.34 million voters.
Of those who took part, 2.02 million Catalans voted "yes" to the question: "Do you want Catalonia to become an independent state in the form of a republic?"
The preliminary results pave the way for the region's leader to declare independence in the coming days, despite the Spanish government ruling the referendum illegal.
Catalan referendum results
The brutal scenes of police cracking down on the referendum plunged the EU into a new crisis after hundreds of people were injured in the violent stand-offs with Spanish police.
In violent scenes beamed around the world, officers in riot gear fired rubber bullets into crowds and beat would-be voters with batons as they queued at polling stations.
The Catalan government claimed 844 people were injured.
There was widespread condemnation of the Spanish government's attempt to crack down on the vote, which Catalan authorities had called despite the courts ruling it illegal.
However, the European Union remained conspicuously silent on the police tactics, which saw masked officers smash their way into polling stations and forcibly remove ballot boxes.
Carles Puigdemont, the Catalan leader, said the region had "won the right to an independent state" after "millions" turned out to vote in a banned independence referendum.
"With this day of hope and suffering, the citizens of Catalonia have won the right to an independent state in the form a republic," he said in a televised announcement after polls had closed.
Before the results were announced, he said he would keep his pledge to declare independence unilaterally within 48 hours of the vote if the "Yes" side won the referendum.
"Today the Spanish state wrote another shameful page in its history with Catalonia," he said, adding that he would appeal to the European Union to look into alleged human rights violations during Sunday's vote.
Violence broke out across Catalonia as armoured police moved in to break up the vote.
Video footage showed officers from Spain's national police - 4,000 of whom had been brought in by the government to help quash the ballot - fighting with elderly voters, some of whom were left bleeding, and dragging young women away from polling stations by their hair.
Amid tense scenes, uniformed Catalan firefighters appeared to act as human shields to protect voters from advancing lines of police.
Responding to the unfolding crisis, Boris Johnson, the Foreign Secretary, told the Daily Telegraph last night: "Obviously we are very anxious about any violence. We hope that things will sort themselves out, though clearly you have to be sensitive to the constitutional proprieties."
He added: "As I understand it the referendum is not legal, so there are difficulties."
Nicola Sturgeon described the Foreign Office's statement as "shamefully weak".
"A true friend of Spain would tell them today’s actions wrong and damaging," Scotland's First Minister said.
Andrew Rosindell, a Tory MP who sits on the Foreign Affairs Select Committee, said he believed the European Union’s response would have been much stronger if such scenes were playing out in other EU countries.
He told the Daily Telegraph the European Union was "showing itself again to be completely hypocritical".
Mr Rosindell accused the Spanish government of trying to “bully the people” and that the violence “shows both Spain and the EU in a very bad light”.
He said: “For years the Spanish have used the Guardia Civil to make life as difficult as possible for Gibraltar and they are using the same police force again to attack the people of Catalonia.
“In other circumstances there is no doubt the EU would be coming down like a tonne of bricks. They are demonstrating double standards: If this was happening in Hungary or another country there would certainly be a different reaction.”
While some MEPs including Guy Verhofstadt - the parliament's Brexit negotiator - condemned the police violence as 'disproportionate', the European Commission said it would not respond to the crisis until Monday.
Catalan referendum in pictures
European leaders were also noticeably silent. The only voice emerging from Brussels was that of the Belgium prime minister, Charles Michel.
On Twitter, he called for political dialogue to resolve the crisis, insisting: “Violence can never be the answer!”
Spain, meanwhile, did not waver in its assertion that the referendum - which was ordered suspended by the Spanish constitutional court - is illegal, and that its hand has been forced by a Catalan government it claims is engaged in a coup.
Spain's foreign minister Alfonso Dastis said the violence was "unfortunate" and "unpleasant" but "proportionate", blaming the violence exclusively on Mr Puigdemont and his regional government.
Spanish Prime Minister Mariano Rajoy last night said: "We did what we had to do", describing the ballot as a “premeditated attack on the legality of the Spanish state faced down with serenity by the forces of order”.
Making no mention of the large number of people injured in police charges outside polling stations, Mr Rajoy said: “Democracy won today because the Constitution was upheld”.
He said the police 'performed their duty' in Catalonia.
The Spanish deputy prime minister, Soraya Sáenz de Santamaría, blasted the Catalan government’s “irresponsibility” in insisting on holding an “illegal referendum with no democratic guarantees”, demanding that they end what she described as a “farce”.
The Catalan government contends it has been forced to go ahead with the unilateral poll, saying it has been left no other option after the central government consistently refused substantive negotiations over the region’s status.
In the event of a "Yes" vote, Mr Puigdemont plans to make a unilateral declaration of independence 48 hours after the results, which are expected to be announced Monday.
In pictures: Catalan farmers block streets and protect polling stations
He told The Telegraph last week that he would then be seeking dialogue with Spain and the European Union, insisting that Europe could no longer "keep looking the other way".
Mr Puigdemont insisted Sunday that the poll had been carried out successfully despite the police crackdown, with voting taking place in 95 percent of polling stations.
"Batons against ballot boxes, violence against public spirit," he said, claiming "the shame will stay with (Spain) forever". Security concerns even had an impact on Sunday’s football.
FC Barcelona initially suspended its home match against Las Palmas as a precaution, but ended up playing behind closed doors after Spain’s RFEF federation rejected the postponement.
The European Commission, the EU’s civil service, has repeatedly backed the Spanish government and constitutional court’s stance that the vote is illegal.
Yesterday the EC told The Telegraph it had nothing to add a statement made by Jean-Claude Juncker on Friday, when he backed “the rule of law” in Spain.
But human rights groups and politicians from around the world contended that regardless of the legality of the poll, the heavy-handed response went beyond what was unacceptable in a 21st century democracy.
Andrew Stroehlein, of Human Rights Watch, said that despite the court suspension, the government had a duty to protect the rights to peaceful assembly and freedom of expression.
The EU would “have to say something more soon,” he suggested. Catalans have expressed particular concern about the use of rubber bullets, which the Catalan police force are banned from using, and which left one person needing eye surgery yesterday.
How Catalonia is so important to Spain
There were suggestions from several quarters that the Commission was taking a much laxer stance on Spain, a valued member of the EU core with an important stake in Brexit negotiations, than it would against other member states.
“The fundamental rights of EU citizens are being damaged by this disproportionate use of violence against peaceful citizens,” Amadeu Altafaj, the permanent representative of the Catalan government to the EU in Brussels told the Telegraph.
“For some countries like Poland there are strict standards but when it comes to Spain, there seems to be a lot of complacency.”