Barcelona defender Gerard Pique says he will retire from international football before the World Cup if his support for Catalonia's independence referendum is deemed a problem.

Barcelona beat Las Palmas 3-0 in an empty stadium on Sunday following unrest in the city, and the 30-year-old described it as his "hardest game".

"I think I can continue," said Pique.

"But if the board really thinks I'm a problem, I will take a step back and leave the national team before 2018.

"There are many people in Spain who disagree with what happened today and believe in democracy."

Catalonia, a region of 7.5 million people in north-eastern Spain, has its own language and culture and Barcelona is its capital.

It also has a high degree of autonomy but is not recognised as a separate nation under the Spanish constitution.

Jeered during Spain games

Pique has played 91 times for Spain but has become a divisive figure because of his stance on the referendum.

During their June friendly against Columbia in Murcia, a city in south east Spain, he was jeered frequently by supporters who oppose Catalan independence.

Real Madrid defender Sergio Ramos has intervened to ask fans to show his international colleague "respect".

Before Sunday's game against Las Palmas, Pique posted a picture on Twitter of him voting in the referendum.

The former Manchester United defender wrote: "I have already voted. Together we are unstoppable defending democracy."


'We debated whether to play'

Barcelona's game against Las Palmas was played behind closed doors as a protest after their request for it to be postponed was rejected.

The Spanish government pledged to stop a poll declared illegal on a day of violent protests and unrest.

Pique said: "The board tried to suspend the match, but it wasn't possible. We debated it and the club decided we should play.

"I am and I feel Catalan, today more than ever. I am proud of the behaviour of the people of Catalonia. Voting is a right that must be defended."

Pique believes Sunday's events will cause further political instability in Spain.

"For a moment I couldn't believe it," he told the AFP agency. "I thought they would try to block the vote but they would try to do it in a peaceful manner.

"It wasn't like that, but at least the whole world has seen it.

"This decision has made things a lot worse. It is one of the worst decisions made by this country in 40 or 50 years.

"It has only served to separate Catalonia and Spain more and it will have consequences."