David McKittrick | The Independent The message in the letter to immigrant communities in Belfast could not be starker or more brutal. "Get out of our Queen's country before our bonfire night and parade day," it declared. Emblazoned with a skull, it descended into a mixture of the semi-literate and the directly threatening with the warning: "Other than your building will be blown up." The leaflet was delivered to centres in Belfast representing the city's Islamic, Indian and Polish communities, in advance of this weekend's high point of the loyalist marching season. It has clearly generated worries among those communities, since all three of the centres would not comment on the threat. But Patrick Yu, who heads the Northern Ireland Council for Ethnic Minorities, said the leaflets were designed to threaten and frighten, adding: "It really is more about trying to reignite the issue." Just last month more than one hundred Romanians were flown out of Northern Ireland following a wave of attacks on their south Belfast homes in an episode which received worldwide publicity. Although the letter is marked "Combat 18" and bears loyalist slogans, the authorities do not believe that any local or outside organisation is behind this threat or other racist attacks. The belief is that both the attacks on Romanians and the general pattern of incidents are largely the work of racist individuals, mostly teenagers, in a primitive show of xenophobia and dislike of "outsiders." But the major complication this weekend is that the annual 12th of July celebrations have been extended with several nights of festivities in prospect before the main Orange Order march takes place on Monday. In the evenings loyalists gather round bonfires piled high with waste wood, unwanted furniture and old vehicle tyres.