A weeklong conflict in Ethiopia, which is believed to have claimed hundreds of lives so far, has forced dozens of troops and large numbers of refugees to flee over the border to Sudan, the Associated Press reports. Fighting erupted last week following a dispute between the national government and local leaders in the northern Tigray region. Nobel Peace Prize-winning Prime Minister Abiy Ahmed has vowed to remove Tigray’s leadership, which his government regards as illegal, and each side has blamed the other for causing the conflict. AP reports that some 30 Ethiopian troops fled into Sudan on Monday, where refugee camps have been set up for a stream of fleeing Ethiopians. On Tuesday, the African Union’s commission chairman, Moussa Faki Mahamat, called for the “immediate cessation of hostilities.”