NAIROBI (Reuters) - The United Nations agency for refugees said it was worried about a refugee emergency if more civilians are forced to flee fighting between federal troops and local forces in the Tigray region in northern Ethiopia, the agency’s representative in the country said on Thursday. Sudan has received more than 10,000 Ethiopian refugees since the fighting started and aid agencies say the situation in Tigray is getting dire. The UN is negotiating with both sides in the conflict for humanitarian corridors to be opened, Ann Encontre, UNHCR’s representative in Ethiopia, told Reuters in an interview.