UEFA will receive a report in the next 48 hours from officials at the stadium and the match referee before issuing any possible sanctions.

The Spanish giants could be fined or forced to play their home games behind closed doors or at a different location.

UEFA spokesman William Gaillard said: “The punishment will depend on the gravity of the matter – whether it was the whole stadium or whether it was a small group of people.

“It could range from banning the stadium and making the team play away from their stadium or behind closed doors, to even the exclusion of the team.

“For an issue of violence recently Roma had two games behind away from their stadium. The Slovakia team were made to play one game at a different location after racist chanting against England a couple of years ago.

Black players were taunted with monkey chants during England’s international friendly against Spain at the Bernabeu last week.

Madrid striker Michael Owen, who played in the England game last week but was left out for the Champions League clash, was upset by the chanting he heard at the Bernabeu.

“It’s a bit disappointing to hear that,” Owen said. “There’s been a lot of talk about it over the last week and it’s always difficult to hear that.

“We’ve done really well in England to stamp it out and there are pockets in Europe that can’t stamp it out.”