In 1963, Dr Martin Luther King wrote a letter from a jail cell in Birmingham, Alabama where he was being held following a peaceful demonstration against discrimination. Racism, he said was "like a boil that can never be cured so long as it is covered up, but must be opened with all its ugliness to the natural medicines of air and light, injustice must be exposed, with all the tension its exposure creates, to the light of human conscience and the air of national opinion before it can be cured."

Nearly 50 years later, that ugly boil of racism was uncovered last week in the comment section of the Sunday Tribune's web edition. If you have any doubts about the existence of racism in Ireland, read the response to the killing of 15-year-old schoolboy Toyosi Shitta-bey in west Dublin. The remarks posted by a minority of Irish readers display an explicit and worrying attitude to immigrants. But in modern Ireland, racism is a two-way street and the responses from some in the black community of New Irish are just as concerning.

The view Irish racists hold of black people, Nigerians in particular, is somewhat predictable. They characterise them as loud and lazy. They claim they drive expensive cars, live in government-subsidised housing and get preferential treatment in state benefits. They blame them for problems ranging from Ireland's recession to the spread of Aids.

One poster claimed: "Blacks are hardworking and are goal getters, they made good use of what comes to them and made their lives better. Aye, Africa's thriving, innit blood? It's not like it's an Aids-infested, malaria-ravaged, corrupt sh*thole or anything, is it? Or like it's people have the lowest IQs in the world? Nah, it's all about "the goal getters" – d'ya get me bro? I'm sick of angry, loud, lazy Africans in our country and their gangster-wannabe children – f**k off home lads and your fat wives too (if you can move your fat lazy arses from the beauty salons) because you're not wanted by the majority of people in this country."*

In return, a minority of the black community living in Ireland have just as stereotypical views of their white neighbours. They describe them as alcoholic, jobless wasters who spend their lives moaning and whingeing instead of getting a job. They expound deeply ignorant views of Africa, simply can't contemplate anybody who is different to themselves and allow black people to do jobs they consider beneath them.

One said: "I have been here for 10 years and I can say without shame, IRISH PEOPLE ARE RACIST. Don't hate blacks cause they work harder than you, or because they have your jobs. They work hard to be there. While you are sitting down drinking or having a laugh, we are in nursing homes cleaning your granny's poo so we could pay our school fees. I hate Irish people, if it wasn't for my seeking of better life, I wouldn't even be in this country."*

These views don't hold up to scrutiny, but it doesn't stop the ignorance being peddled by both sides gaining traction. The hurt being inflicted, especially to young black people who have only known life in Ireland and have just lost a friend, is enormous. One anguished poster commented: "2010 and 99.9% of the world is over racism, but there are still some people in this world who can't understand that the only thing that separates white from black is melanin in your skin. We all have hearts, brains, lungs that function in the same way so why hate because of skin colour…" *

Another asked: "I don't even know how to start this because I am so shocked with the amount of racism in this country. I am black and proud and always will be. You white racist scum have brought me to tears with the comments you have left. Have you got no compassion or even a conscience? What is wrong with being black?"*

Anybody who knew him described Toyosi Shitta-bey as a warm, open-hearted boy who had both black and white friends. His teacher Julie Reilly from Hartstown Community School said he was a pleasure to teach. "He was just great, a great guy, very positive with a smile that would brighten up anybody's day… I am paid to teach no matter who is sitting in front of me. That is my job, to teach. I have Nigerians, Moldovans, Lithuanians, Romanians and Irish in my class. Overall it has been a positive experience. They have blended in from day one and are used to being around different cultures."

The best testament to the life of Toyosi Shitta-bey, who spent 11 of his 15 years in Ireland, was in the shared grief of his friends, black and white, who clung to each other for comfort in the wake of his death. Toyosi's Shelbourne football club teammates, both black and white, accompanied him on his last journey to the cemetery. Their grief, like the sorrow of his friends, his family and his Dublin community who marched peacefully yesterday, was colour blind. And that is the most powerful lance of all for the boil of racism.

* comments translated from text-speak