The UN High Commissioner for Human Rights (UNHCHR) has urged Britain to prevent further incidents of xenophobic abuse in the wake of the vote to leave the EU, and to prosecute perpetrators.

Zeid Al’Hussein, Head of the UNHCHR, on Tuesday in Geneva voiced deep concern over reports of abuse targeting minority communities and foreigners in Britain.

He warned in a statement that racism and xenophobia are completely, totally and utterly unacceptable in any circumstances.

"The United Kingdom has by a democratic act decided to take its leave of the EU.

``This should not be interpreted by some individuals that they have licence to take leave of their senses and embrace a mob-like behaviour in respect of vulnerable communities," he said.

Meanwhile, Mutuma Ruteere, the Independent UN Investigator on Racism, Racial Discrimination and Xenophobia, said that some of the abuse and comments reported since the vote "certainly are xenophobic and racist".

"I also note that the government and the Prime Minister has been very categorical in denouncing those practices as well as what has taken place.``Britain had watchdog institutions that monitor racism,’’ he said.

Ruteere added that the situation on ground would serve as a big test for all the institutions that have been put in place over time.

"I'm quite confident and hopeful that actually the institutions that exist can address this problem and nip it in the bud before it becomes a bigger problem."

Meanwhile, a report noted that the British police said that offensive leaflets targeting Poles had been distributed in a town in central England, and graffiti had been daubed on a Polish cultural centre in London on Sunday, three days after the vote.

It noted that the Islamic groups have reported a sharp rise in incidents against Muslims.

Polish and Muslim leaders in Britain have expressed concern about a spate of racially motivated hate crimes following last week's Brexit referendum, in which immigration was a key issue.

British Prime Minister, David Cameron, has condemned the attacks and said he had spoken to his Polish counterpart, Beata Szydlo, to express his concern and to reassure her that Poles in Britain would be protected.