MADRID: Barcelona's La Liga match against Las Palmas remained in doubt less than an hour before kick-off (1415GMT) on Sunday after clashes between police and activists in Catalonia over an independence referendum for the region deemed illegal by the Spanish government.
At least 91 people were injured in the clashes, officials said as Spanish riot police fired rubber bullets and forced their way into activist-held polling stations.
BeIN Sports Spain reported that if the game goes ahead it would be played behind closed doors.
A section of Barcelona fans' groups had called for a peaceful pitch invasion to show their disgust at events at the polling stations.
Huge queues of fans waited outside the 99,000 capacity Camp Nou waiting for an official decision to be made by the football and security authorities.
Both sets of players have arrived at the Camp Nou.
Earlier, Las Palmas announced they will wear a Spanish flag on their shirts as a show of support for a united Spain.
"We have decided to embroider on our shirt a small Spanish flag and today's date, October 1, to quietly demonstrate our hope in the future of this country, and in the good will of those who live in it, in search of the best understanding," Las Palmas said in a statement.
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".
However, Las Palmas criticised Barca's stance for heightening the tension around the match should it go ahead.
"Today Las Palmas pay a visit on an unprecedented day for our country, a day in which the Catalan government have decided to celebrate a referendum against Spanish law, with all the international exposure that events in the Camp Nou will have," continued Las Palmas' statement.
"The public statements in recent days, especially those of our hosts FC Barcelona, have converted this La Liga match into something more than a mere sporting spectacle."
Outspoken Barca defender Gerard Pique posted a picture of him casting his vote early on Sunday morning.
"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.