The Football Association (FA) has called on UEFA to conduct an urgent investigation after England's players were racially abused during their Euro 2020 qualifying win over Bulgaria.
England bounced back from their defeat to the Czech Republic with a thumping 6-0 victory, but it was a match marred by racist abuse from sections of the support in Sofia.
With England 2-0 up midway through the first half, the game was halted and a message relayed over the public address system, urging home supporters to cease their chanting.
There was a further delay between England's third and fourth goals, with the match appearing close to an abandonment as a group of fans were ejected.
The game continued, with Raheem Sterling and Harry Kane scoring to complete the rout in the second half, and the FA has now demanded an immediate investigation from European football's governing body.
"We can confirm that England players were subjected to abhorrent racist chanting while playing in the Euro 2020 qualifier against Bulgaria," the FA stated in a post on the organisation's official Twitter account.
"This is unacceptable at any level of the game and our immediate focus is supporting the players and staff involved.
"As we are sadly aware, this is not the first time our players have been subjected to this level of abuse and there is no place for this kind of behaviour in society, let alone in football.
"We will be asking UEFA to investigate as a matter of urgency."
FA chairman Greg Clarke was in attendance at Vasil Levski National Stadium, which was partially closed as a punishment for previous incidents of racist abuse from some Bulgarian supporters.
"I was up in the stands with some of the FA staff, watching the game and we heard some sounds which sounded like money chanting," Clarke told ITV Sport.
"I came down, I heard more at the side of the pitch and I saw some activity, [by] a group of people in behind one of the corner flags, which was appalling.
"I would like to see a stringent review by UEFA, I know they take racism very, very seriously, so if we say zero tolerance, zero tolerance means zero tolerance.
"With UEFA, we need to really address that but, to be perfectly frank, we still need to address racism in England. We still have it throughout the pyramid, we see examples every week from the professional game to the grassroots game, we shouldn't take the moral high ground, we should join a movement to drive racism out of our game and have zero tolerance for it.
"One of the ends was closed tonight with respect banners up there because of previous problems. UEFA are going to have to think carefully about the levels of abuse they allow players to tolerate and they're going to have to decide who they make an example of one day but that's after a thorough investigation of the facts."