European football chief Michel Platini has repeated calls for countries to clamp down heavily on racist behaviour.
Platini has spoken out after some notable recent incidences of racism in domestic leagues in Spain and Italy.
Last week the Spanish football federation was criticised for being too lenient and fining Villarreal just under £10,000 after a banana was thrown at Barcelona's Daniel Alves by a fan.
That incident received widespread publicity after Alves picked up the banana and ate it - an action which was recreated by numerous players worldwide in a show of support.
In Italy, Atalanta were fined £32,000 after bananas were thrown at AC Milan players. The club were also handed a partial stadium closure but that punishment was suspended for a year.
After years of criticism for being too lenient itself, European governing body UEFA last year toughened up its own procedures regarding racism and has now reminded all national associations to follow suit.
Platini said: "The UEFA executive committee strongly condemns all acts of discrimination and I was outraged by the incidents which took place in recent weeks.
"It is unacceptable for anyone to be racially insulted or abused inside our stadiums, and we simply cannot tolerate it.
"We call on all our member associations and stakeholders to apply a zero-tolerance policy against all forms of discrimination and to follow the UEFA guidelines in sanctioning all guilty parties.
"Our statutes were recently amended to ensure all UEFA member associations adopt effective policies to eradicate racism."
UEFA's guidelines state clubs must be punished by partial stadium closure for a first such occurrence of racial behaviour by supporters, followed by a full stadium closure and a fine of £40,600 for a second incidence.
A points deduction or expulsion from a competition could follow for another offence.
These procedures were notably seen in action after CSKA Moscow fans racially abused Manchester City's Yaya Toure in a Champions League game last October. The Russian club had to play their next home fixture in the competition in a partially closed stadium.
UEFA also urged stricter application of their "three-step procedure", which empowers referees to stop, suspend or ultimately abandon matches if requests for fans to desist in racist behaviour is ignored.
General secretary Gianni Infantino said: "The fight against racism is a process which we started some time ago.
"It is something we can never stop fighting. Never put the guard down, always keep saying it.
"We have put this in our regulations and been quite harsh this year with several partial stadium closures, even full ones.
"There is a process to be done of convincing everyone to be the same, but it is not just a reason to say it is only just a few idiots somewhere - there cannot be a justification.
"The feeling, seeing what is happening around, was we should express this once again very strongly, and our job is to convince everyone to fight as hard as possible against racism."