United Nations peacekeepers have positioned armoured personnel carriers and are patrolling an area in Sudan where units made up of Northern and Southern Sudanese troops clashed last week, killing 54 soldiers and wounding 85 others. 'The United Nations urges the parties to remain calm and exercise caution,' spokesman Martin Nesirky told a news briefing in New York, referring to the outbreak of violence in Malakal in Sudan’s Upper Nile State between 3 and 5 February.