Catalan officials say at least 337 people have been injured in clashes as Spanish riot police tried to halt a banned referendum on a split from Spain as Madrid asserted its authority over the rebel region.
The Spanish government has pledged to stop a poll that was declared illegal by the country's constitutional court.
Police officers were preventing people from voting, and seizing ballot papers and boxes at polling stations, whereas defiant Catalans shouted ‘Out with the occupying forces!” and sang the anthem of the wealthy northeastern region.
In the regional capital Barcelona, police used batons and fired rubber bullets during pro-referendum protests.
Despite the police action, hundreds-strong queues of people formed in cities and villages throughout the region to cast their votes. At one Barcelona polling station, elderly people and those with children entered first.
The latest injury toll was confirmed by a spokesman for the Catalan regional government, as well as the region's health department.
Separately, the Spanish interior ministry said 11 police officers had been hurt.
At a press conference, Spain's Deputy Prime Minister Soraya Saenz de Santamaria said police had "acted with professionalism and in a proportionate way".
Catalan leader Carles Puigdemont condemned the action of the national police and Guardia Civil, who were sent into Catalonia in large numbers to prevent the vote from taking place.
“The unjustified, disproportionate and irresponsible violence of the Spanish state today has not only failed to stop Catalans’ desire to vote ... but has helped to clarify all the doubts we had to resolve today,” he told reporters.
Spanish Interior Minister Juan Ignacio Zoido blamed Puigdemont for what he termed the day's senseless events.
And the Guardia Civil tweeted (in Spanish) that it was "resisting harassment and provocation" while carrying out its duties "in defense of the law".
Around 70 polling stations had been raided by police, Zoido said.
The aim of the raids was to seize referendum material and not to target people wanting to vote, another senior government official said.
The ballot papers contain just one question: "Do you want Catalonia to become an independent state in the form of a republic?" There are two boxes: Yes or No.
Ahead of the polls opening, the Catalan government said voters
In Girona, riot police smashed their way into a polling station where Puigdemont was due to vote.
Television footage showed them breaking the glass of the sports center's entrance door and forcibly removing those attempting to vote.
However, Puigdemont was still able to cast his ballot at another polling station.