Chelsea defender Antonio Rudiger has urged Tottenham Hotspur to find and punish the individuals who allegedly directed racist abuse at him during Sunday's Premier League match.
The German was involved in an incident in which Tottenham's Son Heung-min was red-carded in the 62nd minute and indicated shortly afterwards he had been the victim of a monkey gesture from the home section.
The Professional Footballers' Association (PFA) called for a government inquiry into racism in the English game following the match, which Chelsea won 2-0.
"I really hope that the offenders will be found and punished soon, and in such a modern football ground like the Tottenham Hotspur Stadium with dozens of TV and security cameras, it must be possible to find and punish them," Rudiger tweeted.
"If not, then there must have been witnesses in the stadium who saw and heard the incident. It's just such a shame that racism still exists in 2019. When will this nonsense stop?"
Tottenham have vowed to take the "strongest possible action" if any fan is identified as having made racist gestures.
Rudiger is the latest Premier League player to suffer alleged racist abuse in a match, with Manchester United's Fred targeted by a Manchester City fan earlier this month.
A series of racist incidents have tainted European soccer recently too, with Inter Milan's Romelu Lukaku and Brescia's Mario Balotelli subjected to racist insults from rival fans during Serie A matches in Italy this season.
"It's really sad to see racism again at a football match, but I think it's important to talk about it in public. If not, it'll be forgotten again in a couple of days (as always)," Rudiger added.
"I don't want to involve Tottenham as an entire club into this situation as I know that just a couple of idiots were the offenders. I got a lot of supportive messages on social media from Spurs fans as well... thank you a lot for this."
The Professional Footballers' Association called for a government inquiry into the alleged racist abuse hurled at Rudiger.
Chelsea's German defender was involved in an incident that saw Tottenham's Son Heung-min red-carded just past the hour mark and shortly afterwards indicated that he had been the victim of a monkey gesture from the home section.
Several announcements were made over Tottenham's public address system saying "racist behaviour from spectators is interfering with the game" while referee Anthony Taylor stopped the game to talk to the players.
"We are disgusted and dismayed that once again, a Premier League fixture has been tainted by abuse from the stands towards players," the PFA said in a statement.
"It has become clear that football players are on the receiving end of the blatant racism that is currently rife in the UK, but they are not alone.
"The PFA calls for a government inquiry into racism within football and encourage the establishment of an All-Party Group at the Department for Digital, Culture, Media and Sport."
Tottenham have also vowed to take the "strongest possible action" if any fan is identified as having made racist gestures.
The club said the correct protocol had been adopted for the one reported incident. UEFA's three-step protocol states that a game can be abandoned if fans have been warned twice before.
"My understanding is that there was a racist comment or gesture. I know Antonio reported it to (captain) Cesar (Azpilicueta) out on the pitch," Chelsea manager Frank Lampard said.
"They are now talking to the officials and going through the right procedure. No matter what stadium it is in, we do not want that in the game."
Tottenham issued a statement saying they would be conducting a "thorough investigation" and would liaise with Chelsea.
"Any form of racism is completely unacceptable and will not be tolerated in our stadium," Tottenham said in a statement.
"We take any such allegations extremely seriously and shall take the strongest possible action against any individual found to be behaving in such a way, including stadium bans."
Chelsea captain Cesar Azpilicueta said the incident happened after the red card to Son, after he kicked out at Rudiger following a tussle.
"Toni came to me and said he was listening in the crowd monkey noises," the Spaniard said. "I reported it to the referee. We have to work together to eradicate the problem. It is an issue in life and football.
"It is made very clear to us all that if we have heard any racist incident to report it. Altogether we need to make it stop."
The alleged racist incident is the latest one at a high-level Premier League game.
Others include Manchester United's Fred claiming he was victim of a monkey gesture by a Manchester City fan. In July, Chelsea banned one of their fans for life after he racially abused Manchester City's Raheem Sterling.
Tottenham defender Toby Alderweireld said players were "sick of it" when asked about the incident while Tottenham manager Jose Mourinho said "every club was together" in the battle to eradicate racist behaviour from the stands.
"I was losing, I didn't want the game stopped but immediately when I knew the reason why it was stopped I obviously understood and accepted it," he said.
"The club is also a very proud club in this kind of situation and the club also internally will try to delete it.
"I'm disappointed that things like that still can happen, but the referee stopped the game. He spoke to the players, he spoke to the captains, he spoke with the coaches."
Guardiola takes dig at Premier League, says 'thank you' for busy festive season
Manchester City manager Pep Guardiola has written to the Premier League to "thank" them for a demanding schedule over the festive period with two matches in less than 48 hours.
Champions City, who trail league leaders Liverpool by 11 points, visit Nuno Espirito Santo's Wolverhampton Wanderers on Friday before hosting Sheffield United on Sunday and Guardiola said it left his players with little recovery time.
"I wrote to the Premier League to say thank you and we're going to the fridge after Wolves to get ready for Sheffield United," a sarcastic Guardiola, whose side defeated second-placed Leicester City 3-1 on Saturday, told reporters.
"Tomorrow (Sunday) is a day off, we're training on the 23rd and 24th. The night of the 24th is off, the morning of the 25th off. Then 26th training and then 27th is Nuno's team."
Guardiola said it was "unrealistic" for his team to retain their league title from their current position, but added that they would not stop chasing unbeaten Liverpool.
City have 38 points from 18 games having played one match more than Juergen Klopp's side, who won the Club World Cup in Doha on Saturday.
"When a team has 16 (league) victories from 17, it's unrealistic to think we're going to chase them," he added.
"It's unrealistic right now. We have to try to win our games, secure Champions League for next season and then you never know."
Pogba's return to Man Utd side only positive from Watford loss: Solskjaer
Manchester United midfielder Paul Pogba's return from injury was the only positive from Sunday's 2-0 Premier League defeat at bottom-placed Watford, manager Ole Gunnar Solskjaer said.
Frenchman Pogba, who has recovered from an ankle problem, came off the bench in the second half for his first appearance since facing Arsenal on Sept. 30 and looked lively though he failed to prevent United from dropping to eighth in the table.
"The big plus is Paul coming on, and that's the one plus," Norwegian Solskjaer told the BBC. "He added urgency, quality, some great passes.
"The boy has been working hard. He's fit and leaner. He'll bring us a lot. He's important... he makes us create chances."
Solskjaer rued his team's lack of urgency in the game where they dominated possession.
"The first half it could easily have been my testimonial. And it might have been a better atmosphere at my testimonial. It was subdued, slow, no tempo, urgency," Solskjaer added.
"We have started off something with the rebuild but today I'm disappointed because you have to come to these stadiums and get more points against teams like today."
Watford boss Nigel Pearson backed his side to climb out of the relegation zone following their first home win this season.
"We're in a difficult situation but we can get out of it," Pearson said.
"We have to do anything we can to win... I've seen lots to encourage myself that we're capable. We have to sustain our positive intent and our ability."
Aston Villa midfielder McGinn suffers fractured ankle
Aston Villa midfielder John McGinn is facing an extended spell on the sidelines after fracturing his ankle in the 3-1 defeat by Southampton at the weekend, the Premier League club have said.
The 25-year-old Scotland international was substituted eight minutes into the game on Saturday and manager Dean Smith said that McGinn was injured after getting his studs caught in the turf.
"The club can confirm that John McGinn suffered an ankle fracture during ... (Saturday's) match with Southampton," Villa said in a statement on Twitter.
Villa, who dropped into the relegation zone after the defeat, did not give a timeframe for McGinn's return. The Birmingham-based club are now 18th in the table on 15 points and next face Norwich City in the league on Thursday.