Let's try and put this in perspective before the Kentucky Militia start watching out for black helicopters over the words "UN" and "threats". The Nigerians are there with UN backing and right now they are more relevant than any other international military force in Sierra Leone, including the British. They have been taking quite a few casualties and yet are still on the receiving end of comments such as the semi-official British one of "we are doing 10 times more with 10 times fewer troops", and taking casualties is something unlikely to happen to our soldiers in Africa after we got our butts kicked in Somalia (do I feel another Hollywood heroes movie coming on).
What has actually happened is that the Nigerians have reacted in typical African Third World Toilet fashion, namely that they are so jealous of the attention that the British super soldiers are receiving that they will shoot any on site as suspected white mercenaries unless given prior notice of all British patrols. The fact that all the rebels are black and couldn't afford "white mercenaries" if they pilfered every bank from Freetown to Casablanca doesn't really bother the Nigerians, they simply want to show that he who has the biggest army makes the rules.
Following the recent events in Zimbabwe it seems that the racist comments made by that country's Agriculture Minister, namely that "Africa should be for black people only" would unfortunately appear to be gaining credibility.
Mike H