Fifa president Sepp Blatter has spoken out about racism in football after allegations of racist chanting during an England U21 game.
The 76-year-old avoided commenting directly on claims of racist chanting directed at English players during the game in Serbia on Tuesday night.
But he tweeted twice and called for discrimination to be "eradicated".
He wrote: "Saddened every time I hear about racist incidents in football.
"We must keep fighting to eradicate discrimination from our sport. Kick racism out of football."
It comes after the Serbian FA denied allegations of racist chanting during the playoff game, which England won 1-0 to go through to the European Championship finals.
The Serbian FA also claimed England player Danny Rose behaved in a "vulgar" manner towards its fans. Rose was sent off after the final whistle.
In a statement on its website, the Serbian FA said: "(The) FA of Serbia absolutely refuses (sic) and denies that there were any occurrences of racism before and during the match at the stadium in Krusevac.
"Making connection between the seen incident - a fight between members of the two teams - and racism has absolutely no ground and we consider it to be a total malevolence.
"Unfortunately, after the fourth minute of the additional time and the victory goal scored by the guest team, unpleasant scenes were seen on the pitch.
"And while most of the English team players celebrated the score, their player number three, Danny Rose, behaved in inappropriate, unsportsmanlike and vulgar manner towards the supporters on the stands at the stadium in Krusevac, and for that he was shown a red card."
The Serbian FA said preliminary reports from the match officials made no mention of racism and added: "We expect that the human and sports culture of our football friends from England will win over the spread of misinformation."
Rose was controversially sent off by the referee after responding angrily to the abuse and kicking a ball into the crowd.
The English FA and Prime Minister David Cameron have called for UEFA to investigate allegations that England players were subjected to racist chants and pelted with seats, coins and stones during the play-off.
In amateur footage of the scuffles that broke out following England's winning goal, monkey chants are clearly audible.
Rose told Sky Sports News: "I just expressed my emotions as soon as we scored.
"Next thing I turned round and all the Serbian players have surrounded me, pushing me, and then a brawl broke out.
"I remember getting slapped twice and then I got ushered away. That's when I kicked the ball and the referee's sent me off.
"As I was walking off there was monkey chanting - but the monkey chanting started long before I got sent off."
He added: "They have to be banned."
Downing Street said Prime Minister David Cameron was "appalled" by the scenes at the end of the match and wants Uefa to impose tough sanctions if racism is proved.
Sports minister Hugh Robertson has also written to Uefa president Michel Platini urging tough action following the "disgraceful scenes".
Captain Jordan Henderson praised his players for their reaction to the alleged racist abuse and called on Uefa to take the appropriate action.
The Football Association reported "a number of incidents of racism" to Uefa after ugly scenes marred a 1-0 win for Stuart Pearce's team in the second leg of their play-off.
FA general secretary Alex Horne said: "We call on UEFA to take the strongest possible action against the Serbian FA, their supporters and anyone found guilty of being involved in the numerous instances of violence and abuse."
Liverpool midfielder Henderson said on www.thefa.com : "There was a lot of racist abuse out there from the stands and a lot going on after the game, which is hard to take for the players."
The brawl broke out when supporters invaded the field moments after Connor Wickham's stoppage-time goal secured a 2-0 aggregate win and a place at next year's finals in Israel.
Henderson added: "The players coped with the abuse really well. It's not nice. They kept their heads and were professional.
"I thought our players were brilliant and conducted themselves very well. The players completely condemn what happened.
"There were also stones, coins and seats getting thrown at us. I didn't understand why Danny Rose was sent off at the end - I didn't see he did anything wrong, other than get abused."
A statement from the FA read: "The FA condemns both the scenes of racism and the confrontation at the final whistle during which time our players and staff were under extreme provocation.
"The FA has reported a number of incidents of racism to Uefa following the fixture.
"These were seemingly aimed at a number of black England players by the crowd. The matter is now with Uefa."
England manager Stuart Pearce said Serbia's technical director Savo Milosevic had visited the England dressing room to apologise.
"I never like to see any football matches end like that," Pearce told ESPN.
"I think there were one or two racist incidents that came on from the crowd. It's in (Uefa's) hands now.
"It's very sad, to be fair, but we're united as a team. I'm very proud of the reaction of our players."