Racist abuse heard from a soccer crowd in Bulgaria on Monday (October 14) night.
Monkey noises, Nazi salutes and chants were directed at black players representing England during a qualifying match for Euro 2020 in Sofia.
Bulgaria's coach and several of his players said they did not hear any racist abuse.
Despite that, the President of the Bulgarian FA, Borislav Mihaylov, has quit his job after the country's Prime Minister urged him to resign following Monday's events.
The game was stopped twice by the match referee under a three-step UEFA protocol to stop racial abuse from crowds.
During the match, England players - including
Class="kln">Aston Villa's Tyrone Mings, who was making his international debut - reported the racist chanting to manager Gareth Southgate.
The referee was then informed and a public anouncement made whilst play was stopped - on two occasions.
Southgate said the players then made a collective decision to continue after halftime.
(SOUNDBITE) (English) ENGLAND MANAGER, GARETH SOUTHGATE, SAYING: "I'm incredibly proud of all the players and all of the staff.
Of course, we could be criticized for not going far enough, but I think we've made a huge statement and frankly, we were in an impossible situation to get it right to the satisfaction of everybody." Under the three-step protocol a referee stops play and makes an announcement for supporters to stop racist behavior.
The second stage sees the match suspended, players sent to the dressing rooms and another warning given to fans.
In the third and final step the referee abandons the match if the chanting doesn't end.
The game - which England won 6-0 - was being played in front of a reduced crowd after UEFA ordered a partial closure of the stadium.
That was a punishment for racist behavior by Bulgaria supporters in June's qualifiers against the Czechs and Kosovo.
UEFA will carry out an investigation into Monday night's incidents.