Barcelona held 0-0 by Madrid amid separatist protest at Camp Nou

The draw left both teams locked on points with Barca in front on goal difference

Barcelona held 0-0 by Madrid amid separatist protest at Camp Nou Real Madrid's Sergio Ramos (centre) and Raphael Varane (right) challenge Barcelona's Lionel Messi (down) during the El Clasico match at the Camp Nou Stadium | AFP

Barcelona and Real Madrid played out a 0-0 draw for the first time in 17 years in a politically supercharged 'clasico' match played amid a large separatist protest that turned violent outside Camp Nou stadium.

The game inside the stadium was completed without any major incidents either on the field or in the stands. But in the streets outside on Wednesday, a detachment of riot police clashed with protesters soon after the start, and plastic trash cans were set on fire.

The smell of smoke from the streets outside reached the stands in the final minutes of the match.

The draw left both teams locked on points atop the Spanish league with Barcelona in front on goal difference. It was the first scoreless match between the fierce rivals since November 2002.

Despite concerns by police that the protesters could also try to delay or interrupt the match, both teams arrived safely and on time to the stadium escorted by a heavy police detail. Fears of a pitch invasion by protesters in the stands also proved unfounded.

Madrid coach Zinedine Zidane said he was pleased with both the performance and the fact that the game went ahead despite the abnormal circumstances.

"Everything went well for Barca and for Real Madrid, and for football," Zidane said.

"So we can all be happy."

Play was held up around a minute shortly after halftime when some spectators threw dozens of inflatable beach balls on the side of the pitch while shouting independence. Stewards quickly cleared them away.

The public speaker also asked the around 100,000 spectators at Europe's biggest stadium to not use exits at one end of the stadium, apparently for security reasons. Barcelona coach Ernesto Valverde said his team was not affected by the protest since there is always an intense atmosphere surrounding games against Madrid.

"With the tension that the game had already, I saw there were a few yellow balls, but not many. We tried to treat it as normally as possible. People protested, but nothing more," Valverde said.

"As a social event, I don't have an opinion. As a sporting event, we drew."

Before kickoff the spectators at the 99,000-seat Camp Nou held up red, blue and yellow square cards to form a mosaic during the playing and singing of the club hymn.

Separatists unfurled a large banner reading "SpainSitandTalk" and "FREEDOM" as calls for the Spanish government to accept a negotiation over a possible referendum on secession. When the hymn was over, some spectators held up blue signs with the same message while shouting for the release from prison for several leaders of the movement.

The separatists want the wealthy northwestern region to break away from the rest of Spain. Catalonia's 7.5 million residents are roughly split by the secession question, according to polls.

While both teams are more known for their high-powered attacks, it was defenders who stood out in the game as Barcelona's Gerard Pique and Madrid's Sergio Ramos both cleared goal-bound shots from their lines.

Ramos set a new record for the most clsicos by a player from either side with 43. The Spain captain blocked Lionel Messi's best chance in the 31st minute.

Led by Messi, who thrilled the crowd from the start with several runs through Madrid's midfield, the hosts appeared in control.

Madrid, however, took the initiative by trying to take advantage of its superior height and bombarded the box with crosses. Pique cleared Madrid's best opportunity, a header from Casemiro in the 17th.

The second half was one of the tamest between the fierce rivals in recent memory. Neither generated much in attack. And even Messi was off key when he scuffed a shot from close range.

As smoke from outside wafted down, the tension shifted from the pitch to the clashes outside. The match ended with an eerie silence. There were no cheers and the tradition of playing the hymn was forgone.