U.N. spokesman Stephane Dujarric told reporters Thursday that six U.N. staff members had been released but five others, along with one of their dependents, remain in detention in Addis Ababa.
At least 16 U.N. staff and dependents were detained earlier this month amid reports of widespread arrests of ethnic Tigrayans.
"Further ethnic profiling can only deteriorate this serious dynamic and can lead to a situation for which we have alarming precedents," said Alice Wairimu Nderitu, the U.N. special adviser of the secretary-general on the prevention of genocide.
In a press release on Wednesday, Nderitu reiterated her concern over the "deteriorating situation" in Ethiopia and strongly condemned "the intensification of profiling and arbitrary arrests of ethnic Tigrayans, including United Nations staff."
"The region has experienced the evil of inter-ethnic violence spiraling down to the commission of genocide," she said. "All possible action must be taken as a matter of utmost urgency to prevent further escalation."
Police have denied making ethnically motivated arrests, contending they are only detaining backers of the rebel Tigrayan forces fighting the Ethiopian government.
Nderitu voiced her concerns the day before the U.S. special envoy for the Horn of Africa, Jeffrey Feltman, and the African Union's high representative for the Horn of Africa, Olusegun Obasanjo, returned to Ethiopia with hopes of reviving peace talks and negotiating a cease-fire in the yearlong conflict.
Nderitu warned during an online event earlier this month of the risk of the war spilling across borders and "becoming something completely unmanageable." She also warned that ethnic-based militias are "so dangerous in this context."
The war began a year ago when Ethiopian Prime Minister Abiy Ahmed deployed troops to the northern regional state of Tigray in response to the Tigray People's Liberation Front's seizure of military bases. The ensuing conflict has killed thousands of people, displaced several million from their homes and left 400,000 residents of Tigray facing famine, according to a July estimate by the U.N.
A joint investigation by the U.N. and the government-created Ethiopian Human Rights Commission published a report in early November concluding that all sides in the conflict have committed human rights violations, including torturing civilians, committing gang rapes and arresting people based on ethnicity.
U.N. High Commissioner for Human Rights Michelle Bachelet has said some of those abuses may amount to war crimes and crimes against humanity.
Some information for this report came from The Associated Press and Reuters.