Demonstrators wave Pro-Independence Catalan flags during a 2014 demonstration as part of the celebrations of the National Day of Catalonia

Catalonia's regional leader opened the door to a unilateral declaration of independence from Spain on Sunday after voters defied a violent police crackdown and, according to regional officials, voted 90 percent in favor of breaking away.

Despite Spanish police using batons and rubber bullets to disrupt the banned referendum, which was declared unconstitutional by Madrid, the Catalan government said 2.26 million people had cast ballots, a turnout of about 42 percent.

Carles Puigdemont's comments followed a television address by Spanish Prime Minister Mariano Rajoy who ruled out independence and accused separatists of trying to "blackmail ...

the whole nation". He offered all-party talks on the region's future.

Catalan officials say more than 800 people were injured in clashes with Spanish riot police during the referendum, which has pitched the country into its deepest constitutional crisis in decades and deepened a rift between Madrid and Barcelona.

"On this day of hope and suffering, Catalonia's citizens have earned the right to have an independent state in the form of a republic," Puigdemont said in a televised address.

"My government, in the next few days will send the results of today's vote to the Catalan Parliament, where the sovereignty of our people lies, so that it can act in accordance with the

law of the referendum," he said.

The law of the referendum, deemed unconstitutional by Madrid, foresees a unilateral declaration of independence by the Catalan parliament if the majority votes to leave Spain. The law does not set a minimum turnout for the outcome to be valid.

The results announced early on Monday were not a surprise, given that many unionists were not expected to turn out to vote.

Earlier in the day, the streets of Catalonia, an industrial and tourism powerhouse accounting for a fifth of Spain's economy, erupted into violence as national police burst into polling stations with batons, dragging voters away.

The action drew criticism at home and abroad. British Foreign Secretary Boris Johnson voiced worries over the violence while backing Madrid's view that the vote was unconstitutional.

Spain's deputy prime minister said force used by the police had been proportionate.

"The absolute irresponsibility of the regional government has had to be met by the security forces of the state," said Soraya Saenz de Santamaria.

The euro lost about a third of a U.S. cent after the violence-marred vote before steadying. It touched a low of $1.1776 in thin Asian trade but soon steadied at $1.1801.

In the run-up to the referendum, Puigdemont had said he would move to a declaration of independence within 48 hours of a "yes" vote. But the fragmented nature of the polling, with many voting stations closed, could complicate any move to a formal declaration.

Puigdemont called on Europe to step in to make sure fundamental rights were fully respected.