POLICE are on heightened alert for a spike in hate crime - with officers in Sussex investigating a referendum-linked offence.

There have been reports of incidents around the country with those of Polish descent being targeted in particular.

Sussex Police is investigating reports of an alleged hate crime involving eleven-year-old girl who was said to be the victim of racially aggravated threatening behaviour by a gang of teenage boys in Southwater Country Park near Horsham on Saturday.

Poland's ambassador yesterday expressed his shock at "xenophobic abuse" against the Polish community while David Cameron has condemned the incidents.

Mayor of London Sadiq Khan has asked Scotland Yard to be "extra vigilant" for any rise in cases.

In Brighton and Hove, council leader Warren Morgan said there would be a "zero tolerance" approach to such behaviour in the city.

Leave campaigner cllr Tom Bewick said he was "sickened" by the hate incidents.

He said: "I want to say how sickened I am about reports of increased hate incidents towards racial groups since the EU referendum.

"The perpetrators are criminals."

Cllr Morgan added: "We have to be clear that there will be continue to be zero tolerance towards racism against fellow residents, students or visitors to our city, and we will work through our community partnerships to ensure that those feeling uncertain and worried are reassured and supported.

"We must bring the city together and make certain that our communities, our businesses and our city come through this period and move on with the work of making a stronger, united and more prosperous Brighton and Hove.”

In Cambridgeshire, police are investigating after cards reading "Leave the EU - no more Polish vermin" were discovered.

An 11-year-old boy named as Matteus, whose family moved to Britain from Poland three years ago, told the BBC he was going to school when he found a card containing the words on Friday.

The boy's father Tomek said: "I live in this country, I pay any taxes. My home is now this country. I do not understand this situation."

In London Scotland Yard is investigating a hate crime incident after offensive graffiti was daubed on the front of a Polish Social and Cultural Association in Ravenscourt Park, west London.

The National Police Chiefs' Council revealed there was an increase of reports to an online hate crime reporting site between Thursday and Sunday compared to the corresponding period four weeks ago.

To report a racist incident call 101 or go to @TellMamaUK on Twitter.