The Mayor of Barcelona criticised a derogatory banner held up by Espanyol fans targeting Shakira, the popstar partner of Barcelona defender Gerard Pique, during the midweek Copa del Rey match.
Barcelona prevailed 2-0 thanks to a Munir brace at Cornella El Prat, the home of their city rivals, to ease to a 6-1 aggregate win in what was often a bad-tempered last-16 tie.
Pique has been the target of abuse from Espanyol previously and he mocked the club's supporters for not being able to fill their groundafter Barca's 4-1 first-leg triumph at Camp Nou.
The banner in question read "Shakira es de todos", which translates as "Shakira is everyone's" and, speaking to RAC1, Ada Colau lambasted those responsible.
"To look at it damages your eyes," she said. "I find it horrible.
"There are certain macho cultural values that can generate macho violence."
Barcelona's club president Josep Maria Bertomeu called on the match officials to ensure action was taken over banners among Espanyol supporters.
These also included a sign praising goalkeeper Pau Lopez for appearing to stamp on star forward Lionel Messi during the first leg, reading "Pau, your foot shows us the way."
"I haven't seen [the banners] but they told me about them," Bartomeu told Sport.
"It's what we talked about [before the game], the referee will have to take note and add it to his report."