Mr Johnson responded: "It is absolutely vital that fans who are preparing to go to Russian Federation for the World Cup, and we are not actively trying to dissuade them, we don't think that would be right, they should look at our keep on the ball website, they should look at the risks that we believe may be associated with any particular venues".
Deputy Chief Constable Mark Roberts, the head of football policing, said the flags were the "trophies of choice for hooligans from rival countries", the Daily Mail reports. "It can come across as nearly imperialistic. and can cause antagonism", he said. The supporters traditionally gather in city centres before worldwide tournaments and display hundreds of flags.
"We would not expect people to come across to this country, get drunk and drape flags on the Cenotaph, so we need to extend the same courtesy when we go overseas", he said. He pointed out that most British football fans were seasoned travellers.
He said: "Some of them have particularly strong opinions about how people in Britain should adopt to our way of life and the corollary of that when we go somewhere else then you have to respect their culture". The Russian city will host England's opening game against Tunisia, but is also city of significant importance to the Russian people.
It is on Russian "honour to guarantee the safety" of England fans travelling to the World Cup, Foreign Secretary Boris Johnson has told MPs.
Mr Roberts, of the National Police Chiefs' Council, said the increased tensions between the two countries after the Salisbury spy poisoning incident could play a role.
Following clashes between Russia and England fans at the 2016 European Championship in Marseille, Russian ultras proudly posted images on social media of "captured" England flags.
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