The Professional Footballers' Association has called for a government inquiry into racism in football after Chelsea's Premier League win at Tottenham was marred by alleged racist behaviour from the crowd.
Referee Anthony Taylor stopped play during the second half after Blues defender Antonio Rudiger complained of hearing monkey noises.
Tottenham have vowed to "take the strongest possible action" and said they will conduct "a thorough investigation".
Shortly after the stoppage, an announcement made over the public address system warned that "racist behaviour is interfering with the game".
Second and third addresses followed with the game heading towards its conclusion.
The PFA said: "We are disgusted and dismayed that once again, a Premier League fixture has been tainted by abuse from the stands towards players.
"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 stands beside every player who faces discrimination. We will continue to fight on their behalf to combat this issue for good.
"Football is part of the fabric of British society - with the huge global audience that English football attracts, we have a responsibility to lead the way with a zero-tolerance policy."
The PFA added that "all governing bodies" and "all football stakeholders" should work together to "confront, challenge and eradicate racist abuse in our stadiums and in our country".
It said: "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."
Spurs confirmed that they will be liaising with Chelsea and their players for their observations.
"Any form of racism is completely unacceptable and will not be tolerated in our stadium," said Spurs 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."
The Professional Game Match Officials Limited (PGMOL) and Tottenham have confirmed that the game was stopped over a single incident of alleged racist behaviour.
Tottenham forward Son Heung-min had been sent off after a second-half clash involving Rudiger moments earlier.
The match was also held up when objects were thrown towards Chelsea keeper Kepa Arrizabalaga.
'When will this nonsense stop?'
Rudiger has since tweeted: "It is really sad to see racism again at a football match, but I think it's very important to talk about it in public. If not, it will be forgotten again in a couple of days (as always).
"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 in the last hours - thank you a lot for this.
"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 subsequently punish them.
"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?"
'He told me he was listening to monkey noises'
In his post-match interview, Chelsea captain Cesar Azpilicueta said: "It is made very clear to us all if we have heard any racist incident to report it.
"Toni came to me and he told me he was listening in the crowd [to] monkey noises and my job as a captain is to go straight to the referee and to report it.
"We are very concerned and aware of the problems. All together we need to make it stop. We have to work together towards the eradication of the problem. It's an issue in life and football unfortunately and we have to keep working hard."
Tottenham manager Jose Mourinho reiterated that view in his post-match interview on Sky Sports.
"I saw nothing. I saw the referee follow the protocol, he came to [fourth official] Andre Marriner, he came to me and Frank Lampard and told us what was happening," he said.
"The protocol was followed and we are one of the clubs; every club is together on this situation and of course we are disappointed."
Tottenham defender Toby Alderweireld added: "It does not belong in football. I hope they find the individuals quickly because it is not good and we are all sick of it."
Speaking at the game, former Newcastle and Tottenham midfielder Jermaine Jenas said: "With the technology they have in this stadium, I would be shocked if they could not pinpoint the individual.
"That person will be isolated and dealt with accordingly. There is no place for it but I want more than an announcement.
"I do not want them back in the stadium ever again - sadly some people are that ignorant."
Anti-racism organisation Kick it Out later released a statement on Twitter.
It read: "We are aware of the alleged racist incidents at today's game between Tottenham Hotspur and Chelsea.
"We applaud the reaction of referee Anthony Taylor in following step one of the protocol and the ensuing steps taken by Tottenham Hotspur in repeating the stadium announcements.
"We have offered our support to both of the clubs and also to Chelsea's Antonio Rudiger."
A year of shame
The incident comes a year after racism in football hit the headlines after Manchester City striker Raheem Sterling was subjected to racist abuse at Stamford Bridge in December 2018, which led to a permanent ban for a Chelsea supporter.
Sterling was also one of a number of England players who faced monkey chants and Nazi salutes in Euro 2020 qualifiers this year.
A supporter was also arrested and bailed over allegations of racist abuse against Manchester United players during their Premier League match at Manchester City on 7 December.
A video had been circulated on social media of a man appearing to make monkey gestures and sounds towards United players at Etihad Stadium.
Serie A's 'No To Racism' campaign - which arrived off the back of a number of racist incidents in Italy - has been widely condemned after they commissioned posters showing three monkeys with painted faces.