The US secretary of state has cut short a three-nation tour of Africa following a volcano eruption that has created an ash cloud over parts of East Africa.
Hillary Clinton arrived in the Ethiopian capital on Monday for an address to the African Union.
US officials said the decision was taken because the cloud was due to move towards Addis Ababa.
The cloud, triggered by an eruption in Eritrea, has led to the cancellation of some flights to East Africa.
The German airline Lufthansa cancelled flights to both Eritrea and neighbouring Ethiopia.