By Nafisa Eltahir KHARTOUM (Reuters) – Up to 550 Ethiopian peacekeepers working in Sudan have sought asylum rather than return home for fear they will be persecuted due to their Tigrayan ethnicity, an official with direct knowledge of the plan said on Tuesday. The soldiers, numbering between 525 to 550, were part of a U.N. peacekeeping force working in Abyei, a contested oil-rich area on Sudan’s border with South Sudan, the official working in refugee response told Reuters on condition of anonymity. Ethiopian government spokesperson Legesse Tulu and military spokesman Col. Getnet Adane did not…