Barcelona pair Lionel Messi and Xavi have revealed their frustration at what they consider unfair officiating during the team's 2011-12 Liga campaign, with Victor Valdes also criticising the standard of refereeing in Spain. Goal.com reported.

The Catalan club fell further behind rivals Real Madrid in the title race after being held to a 0-0 draw at Villarreal on Saturday, while Jose Mourinho's men downed Zaragoza 3-1 to open up a commanding seven-point lead at the top of the table.

Commenting after the final whistle, Argentine maestro Messi led the chorus of Barca players less than happy with the match-day officials.

"Sometimes they are arrogant, and they threaten to pull out a card at the most minor provocation," the Fifa Ballon d'Or winner told reporters after the game.

And his words were echoed by Xavi, who suggested that his team had been targeted by referees.

"I get the feeling that we are being punished more than other teams," was the midfielder's interpretation of events, while goalkeeper Valdes believes the Catalans should have been awarded more spot-kicks this term.

"Over the course of the season, some clear penalties have not been awarded," he said.