The Interior Ministry has confirmed that 16 arrests have been created in connection with the alleged abuse led by the players of England on Monday.
The European Qualifier was stopped twice due to racist chanting from home supporters as his players considered walking off the pitch during the success in Sofia and Gareth Southgate.
On Wednesday, the Interior Ministry said that they had detained six people - and work was ongoing to determine other participants at the incident.
UEFA has started disciplinary action against Bulgaria in the Wake of the clash in the Vasil Levski National Stadium.
Meanwhile, the FIFA say they are"closely monitoring" the Bulgarian Football Union (BFU) following the resignation of its president, after the occasions on Monday.
Bulgaria's captain Ivelin Popov said that he was"ashamed" by what occurred, while their coach Krasimir Balakov apologised to the England team for its racist taunts, after the match.
Gareth Southgate claimed that he was"proud" of his own staff and players for the way they conducted themselves throughout the European Qualifier, amid the challenging circumstances.
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