LONDON — Reports of racial abuse on Britain's streets have spiked following the country's bitterly fought Brexit referendum, campaigners say.
More than 100 alleged hate crimes have been brought to the attention of the Muslim Council of Britain since Friday's result.
Immigration was among the chief concerns of "Leave" voters, according to pollsters, and the "Remain" campaign accused some of its opponents of encouraging racist and xenophobic attitudes.
In the wake of the "Leave" victory — 17.4 million votes to 16.1 million — dozens of people posted on social media that they had suffered or witnessed racial abuse by people apparently using the result to legitimize their views.
Shuja Shafi, the Muslim Council of Britain's secretary, said in a statement that Britain was "witnessing the shocking extent" of the divisions that emerged during the campaign, "with reports around the country of hate speech and minorities being targeted."
Following these reports, London Mayor Sadiq Khan said in a statement Monday he had "asked police to be extra vigilant for any rise in case of hate crime," the Evening Standard reported. Almost 60 percent of Londoners voted "Remain" but Khan said it was important not to "demonize" the 1.5 million people in the capital who voted "Leave."
A Facebook group called "Worrying Signs" was set up to document these reported incidents and by Monday morning gained more than 5,000 members in 12 hours.
"People have been reporting some really harrowing experiences," said group co-founder Natasha Blank, a 32-year-old marketing professional and freelance writer from the English city of Manchester.
Blank was keen to stress that these views were not representative of the vast number of "Leave" voters, some of whom were members of the Facebook group and also condemned the alleged incidents.
She has not had time to analyze how many individual incidents have been posted, nor verify their veracity. But for Blank, whose family heritage is Pakistani, the mood has been undeniable.
"It's so bizarre and difficult to explain but you can almost feel it," she said. "I went with my mother to vote and the air was thick with something insidious."
What had already been a tense campaign boiled over on June 16 just one week before the vote.
Nigel Farage, leader of the right-wing United Kingdom Independence Party, or UKIP, unveiled a poster featuring a line of migrants and refugees crossing the Croatia-Slovenia border in 2015.
Over the image was the text "BREAKING POINT." Some commentators on social media pointed out the image's inadvertent similarities to Nazi propaganda from the 1930s.
Just hours later, pro-EU lawmaker Jo Cox was allegedly murdered by a man who later gave his name in court as "death to traitors, freedom for Britain."
Boris Johnson, former London mayor and leading voice in the Leave campaign, appeared to play down any divisions that had built up during the referendum campaign.
Writing in the Daily Telegraph newspaper, he said sovereignty — relating to the Euroskeptic idea that the EU makes too many of Britain's laws — was the main reason people voted to leave the EU, rather than immigration.
(Most pollsters agree that sovereignty was the main reason people said they voted "Leave," with immigration and border control coming second.)
Among the reported incidents of alleged racist abuse, staff at London's Polish Social and Cultural Association came into work Sunday morning to find "really unpleasant graffiti all across the front of our building," association chair Joanna Mludzinska said.
London's Metropolitan Police said it was investigating the graffiti as "alleged racially motivated criminal damage" but added there had been no arrests.
A spokeswoman for the force told NBC News that officers were looking into media requests for the number of racial abuse reports since Friday. Jess Phillips, a lawmaker for the opposition Labour party, said she would be formally asking the government for the figures.
In Cambridge, laminated signs reading "leave the EU, no more Polish vermin" were found outside schools hours after the result was announced Friday, the Cambridge News reported.
A Polish student who found some of the signs told the newspaper that he "felt really sad" at the message, and police were investigating, according to the report.