Northern Ireland trade union leaders will hold a rally in Belfast city centre today to protest against the spate of racist attacks in the city.

The public protest comes after more than 100 Romanians opted to leave Northern Ireland after racists targeted their homes.

The incident has been followed by threats against other ethnic minority groups in the city.

Police have also warned Alliance party politician Anna Lo - the only member of the Northern Ireland Assembly from an ethnic minority background - that she was also under threat.

Trade unionists have now appealed for the public to gather for an anti-racism rally at Belfast's City Hall at 1pm today.

Irish Congress of Trade Unions (Ictu) assistant general secretary Peter Bunting said: "We are prepared to invest to prevent the spread of swine flu, and measles, mumps and rubella.

"We must invest in the prevention of other social illnesses.

"Racism is a contagious disease. But racism is a preventable disease.

"We can and we must invest in prevention because the cure can be too expensive."

Threats were made this week against Polish and Islamic centres in Belfast.

More than 100 Romanians were forced from their homes in the city earlier this month in an incident that attracted widespread condemnation.

Polish families in Co Tyrone were attacked, as was an Indian centre in Belfast.

Police have said the spate of attacks was not co-ordinated, but the increased attention on the issue sparked an Assembly debate on racism on Monday at which the violence against minorities was widely condemned.

Ms Lo, who was born in Hong Kong but who has lived in Northern Ireland for decades, has championed the cause of ethnic minorities and took part in the debate.

She said the threat to attack her and her home would not deter her from working to improve community relations.

Ms Lo warned a small number of Assembly Members who during the debate condemned racism, but also made references to crime coming from migrant communities, that they risked sending out a dangerous message.

"I am saddened really by some of the comments which to me were defensive and also stereotyping our ethnic minority communities," she said.

"Of course, there are good apples and bad apples in all communities.

"But that is not the cause for racist attacks.

"We need to address racism, hate crimes of all types in our society.

"I have lived here for 35 years. I don't believe that Northern Ireland is a racist society but a small minority can bring us all down in the eyes of the world."

Yesterday the Northern Ireland Council for Ethnic Minorities (Nicem) called on politicians to deliver legislation to directly tackle hate crime.

Deputy First Minister Martin McGuinness has said a draft Cohesion, Sharing and Integration strategy (CSI Strategy), a central part of a plan to tackle issues such as racism and sectarianism, was close to completion.