Lionel Messi scored twice as Barcelona beat Las Palmas 3-0 in a match played behind closed doors after the Spanish league refused to postpone the game on the day of the highly-charged Catalonia referendum.

At least 91 people were injured as Spanish riot police fired rubber bullets and forced their way into activist-held polling stations over the independence vote deemed illegal by the Spanish government on Sunday.

Barcelona president Josep Maria Bartomeu said the club made the decision to play behind closed doors at the 99,000-capacity Camp Nou as a protest against the violent clashes rather than security concerns.

"FC Barcelona condemns the events which have taken place in many parts of Catalonia today in order to prevent its citizens exercising their democratic right to free expression," Barcelona said in a statement.

"We have done it behind closed doors so that everyone can see our opposition at what is happening," added Bartomeu.

In a statement, La Liga insisted "there was no motive for the game to be abandoned".

Had Barca refused to play the game they could have faced a three-point deduction from La Liga on top of forfeiting the match against Las Palmas.

"La Liga's refusal to cancel the game and play it another day... would mean the loss of six points for the team," said Bartomeu.

Outspoken Barca defender Gerard Pique was in tears at the end of the match.

"It was the worst professional experience I have had in my life," he told reporters.

A section of Barcelona fans' groups had threatened a peaceful pitch invasion to show their disgust at events at the polling stations if the game was not suspended.

"It was strange, I didn't like it at all," Barca midfielder Sergio Busquets, a Catalan and World Cup winner with Spain, told BeIN Sports Spain.

"We were aware of what had happened. I think the club evaluated the possibility (of not playing) but on a sporting level that penalised us a lot."

Indeed, despite the closure of the stadium, one fan did make it onto the pitch after Barca's second goal before being quickly hauled off by stewards.

Huge queues of fans waited outside the 99,000 capacity Camp Nou for hours until a final decision was made less than 30 minutes before kick-off.

A Barca spokesperson confirmed that all fans who bought tickets would be reimbursed.

- Messi unmoved -

The match itself was an understandably low key affair as Barca opened up a five-point lead at the top of La Liga and moved 10 points clear of Real Madrid, who host Espanyol later on Sunday.

Barca's players entered the field wearing a training top in the colours of the Catalan Senyera flag over their traditional blue and red home kit.

Meanwhile, Las Palmas wore a small Spanish flag on their shirts as a show of support for a united Spain.

However, all the off-field distractions seemed to affect the hosts in the first-half as Jonathan Calleri came closest to opening the scoring when he hit the post for Las Palmas.

Busquets settled Barca early in the second-half by heading home the opener from Messi's corner.

Messi then took over himself as he calmly rounded Leandro Chichizola from Denis Suarez's excellent pass to make it 2-0.

And the five-time World Player of the Year then smashed home Luis Suarez's through ball for already his 14th goal of the season.

- Pique votes -

Barca have long supported Catalonia's right for a vote on independence, without throwing their weight behind the yes or no camp.

Last week the club released a strongly-worded statement condemning arrests of regional Catalan government figures in "the defence of the nation, to democracy, to freedom of speech, and to self-determination".

According to Spanish media reports, Barca vice-president Carles Vilarrubi has resigned over the club's decision to play the game.

Pique posted a picture of him casting his vote early on Sunday.

"I have voted. Together we are unstoppable defending democracy," said Pique.

Legendary Barca midfielder Xavi Hernandez, who currently plays for Qatari side Al Sadd, also posted a video on social media describing the events as "shameful".

"It is unacceptable that in a democratic country people cannot vote," added Xavi.

And former Barca captain Carles Puyol added his support for the referendum by posting "To vote is democracy!" on his Twitter account.