The African Union is urging Ethiopia and Eritrea to exercise restraint following military movements near their disputed border, warning that tensions could escalate into war.
In a statement, the African Union says the developments could lead to confrontation with far-reaching implications.
The warning echoed the United Nations' fears of renewed conflict between Ethiopia and Eritrea. The two nations fought a two-year border war that left 70,000 people dead.
This week, the U.N. observer mission in the region reported seeing military movements involving tanks and troops near the unmarked border.
A U.N. Security Council envoy, Ambassador Kenzo Oshima, is being sent to the region next week to discuss the developments with U.N. troops.
Peacekeepers have been banned from flying over Eritrean airspace, reducing the world body's ability to monitor the border.
Eritrea has become increasingly angry over the refusal of Ethiopia to accept a new border, drawn by an independent commission as part of a 2000 peace accord.