Espanyol and Athletic Club's 1-1 draw in LaLiga on Sunday was marred by alleged racist chants aimed towards forward Maroan Sannadi from the home supporters.
Athletic forward Iñaki Williams said teammate Sannadi was subjected to the abuse in the 17th minute, when the game was halted after referee Guillermo Cuadra Fernández activated the anti-racism protocol.
A message was displayed on the big screens as an announcement was broadcast warning fans that the next incident would result in the game either being temporarily suspended or even abandoned.
It initially seemed as if Williams, who was continually whistled by Espanyol fans thereafter, was the subject of the insults because he had alerted the referee to the incident, but the Ghana international explained Sannadi, who is of Moroccan origin, was the target.
"You come to football to enjoy yourself," Williams told reporters. "These type of things cannot happen. There was a moment in the first half in the corner when racist abuse was shouted at Maroan [Sannadi] from the stands.
"It's not the first time it's happened here. It happened to me a few years ago as well. Four people should not tarnish all Espanyol's supporters, though. Their full-back [Omar] El Hilali is Moroccan. [Former Cameroon goalkeeper] Thomas N'Kono is a legend here.
"The referee acted well, activating the protocol and putting up the messages on the big screens. I hope there's action against those that abused [Sannadi]."
An Espanyol statement on social media read: "Espanyol once again strongly condemns any display of racism on football pitches."
LaLiga's protocol allows a referee to stop a match if they observe racist behaviour or are alerted to a racist incident by a player.
An announcement is then broadcast over the stadium PA system, explaining why the game has been halted and adding that if the incidents continue, the players will be taken off the pitch.
If, once they return, the behaviour does not desist, the fixture will be abandoned.
"In the moment I didn't know if it was Maroan or Iñaki, just that the referee explained that he had activated the protocol," Athletic coach Ernesto Valverde said in a news conference.
"But it doesn't matter which player it was. We don't like that this happens to our player or to opposition players, in this stadium or in any stadium."
Williams, who is Black, had monkey noises directed him during a match at the RCDE Stadium in 2020. Espanyol identified the 12 fans who had racially insulted the Athletic forward, handing them stadium bans.
There have been multiple cases of racist insults against players in Spanish football in the years since, with Real Madrid forward Vinícius Júnior repeatedly targeted.
LaLiga and the Royal Spanish Football Federation (RFEF) have worked hard to combat racism in the game.
Last June, three Valencia fans were jailed for eight months for racially abusing Vinícius during a LaLiga game in May 2023, the first verdict of its kind in the country.
In September, a court then handed a 12-month suspended sentence to a Mallorca supporter who used racist insults against Vinícius and Villarreal's Samuel Chukwueze in February 2023.
A month later, Spain's national police arrested four people responsible for a hate campaign against Vinícius.
Just last month, meanwhile, Barcelona defender Alejandro Balde said he was racially abused by Getafe supporters during a 1-1 road draw at the Coliseum.