Sofia - Bulgaria's football chief resigned on Tuesday after racist chanting marred England's Euro 2020 qualifier in Sofia, as UEFA chief Aleksander Ceferin said the sport needed to "wage war" on abusers.
As temperatures rose his Bulgarian counterpart, Boyko Borisov, urged the country's football union president to quit.
His resignation came shortly before the BFU's headquarters were raided by special prosecutors and police, although it is not clear if the swoop was related to Mihaylov's resignation or Monday night's abuse of England's black players.
England captain Harry Kane said the team had made a decision to carry on playing but called for tougher punishments.
"Whether any racial abuse should be allowed at any time... well it shouldn't be. The protocol at the moment allows there to be an announcement, there to be two or three steps before the players are taken off the pitch.
British anti-racism group Kick It Out said the game should have been abandoned by officials after TV footage showed that racist abuse continued in the second half.
With England 2-0 ahead, the game was temporarily stopped and a warning played over the loudspeakers in both Bulgarian and English.