The UN Office for the Coordination of Humanitarian Affairs (OCHA) said on Friday that aid agencies needed USD 166 million to help around 628,000 people amid continuing violence in South Sudan. OCHA said in a statement that due to ongoing violence in that area some 200, 000 people have taken refuge in and around UN bases, which led to expansion of UN aid offices to reach small towns and villages. UN humanitarian coordinator for South Sudan Toby Lanzer in a different statement that "this is an extremely difficult time for the people of this new nation, and it is crucial that aid agencies have the resources they need to save lives in the coming months," he added. He expressed hope that donors would "act swiftly" to raise the necessary funds. Violence began spreading across South Sudan after a fight among the presidential guards on December 15, pitting soldiers from President Silva Kiir's Dinka ethnic group against those from the Nuer ethnic group of former Vice President Riek Machar. OCHA is the part of the United Nations Secretariat responsible for bringing together humanitarian actors to ensure a coherent response to emergencies.