One Twitter user, Ben Zen, wrote that two Britons waved an English flag towards him and, having heard him speak in Romanian, said: "We voted you out. Go home you f*****g immigrants."

Another, Carlos from London, posted images of a Polish father and son who had been severely beaten, reporting that the family members had said Englishmen were behind the attack.

On Facebook, Ai Sha shared a video showing members of the far-right English Defence League gathering outside a mosque in Birmingham waving a flag that read: "Rapefugees Not Welcome", as they shouted "f*****g p**dos" and "Allah, Allah, who the f*** is Allah?". Police later made two arrests.

John O'Connell, from anti-racism group Far Right Watch, said they had recorded more than 90 incidents in the past three days, ranging from "verbal abuse up to physical violence".

“I’m not racist. I don’t want to offend you,” a cafe worker kept telling me, plainly not caring whether she did. I tried it again in Dorset the weekend before the ballot, with a couple clutching Vote Leave signs. The woman detailed her daughter’s difficulty in getting housing in London, the groping on public transport, a cooking fire in the flat below with five eastern European men. She shook with anger. “I just want my country back.”

Neo-nazi skinhead groups [involved in Sacramento's violent melee] have promised to defend Donald Trump supporters at the upcoming Republican National Convention in Cleveland next month, Traditionalist Worker Party spokesman Matt Parrott told McClatchyDC on Monday.

"We're essentially just going to show up and make sure that the Donald Trump supporters are defended from the leftist thugs," Parrot told McClatchy in an exclusive interview.

Traditionalist Worker Party leader Matthew Heimbach had previously gained notoriety for assaulting a young black female protester while wearing a "Make America great again" baseball cap at a Trump rally in Louisville, Kentucky, earlier this year.

Supporters of U.S. presidential candidate Donald Trump are more likely to describe African Americans as “criminal,” “unintelligent,” “lazy” and “violent” than voters who backed some Republican rivals in the primaries or who support Democratic contender Hillary Clinton, according to a Reuters/Ipsos opinion poll.

Ahead of the Nov. 8 election to replace Barack Obama, the first black U.S. president, the poll also showed significant numbers of Americans in both the Republican and Democratic parties view blacks more negatively than whites, harbor anxiety about living in diverse neighborhoods and are concerned that affirmative action policies discriminate against whites.

Republicans in the survey expressed these concerns to a greater degree than Democrats, with Trump supporters presenting the most critical views of blacks.