England's European Championship qualifier in Bulgaria had to be temporarily halted twice due to racist abuse aimed at the away players.
The Three Lions raced into a 4-0 lead before half time, but the main point of note in the opening 45 minutes came in the stands.
Harry Kane complained to the referee, who stopped the game and ordered an announcement to be made.
A number of home fans did leave the stadium before the second half.
Bulgaria were playing with 5,000 seats already empty due to racist abuse in their previous games against the Czech Republic and Kosovo.