The UN did not specify who carried out the strike but only that the Ethiopian government has air power in the area.
An air strike has hit a refugee camp in northern Ethiopia's Tigray region, killing three Eritrean refugees, including two children.
The strike on Wednesday hit Mai Aini refugee camp near the southern Tigrayan town of Mai Tsebri, the United Nations said on Thursday.
"Three Eritrean refugees, two of them children, were killed," the United Nations High Commission for Refugees (UNHCR) head Filippo Grandi said in a statement, adding that four other refugees were injured.
Ethiopia repeatedly denies targeting civilians
Government spokesperson Legesse Tulu and military spokesperson Getnet Adane did not immediately respond to requests for comment.
The government has previously denied targeting civilians.
At least 146 people have been killed and 213 injured in 41 air strikes in Tigray since Oct 18, according to a document prepared by aid agencies.
The deadliest being a Dec 16 strike in the town of Alamata that killed 38 and wounded 86.
The 14-month-old war in northern Ethiopia between the federal government and the Tigray People's Liberation Front (TPLF), which used to dominate Ethiopian politics, has killed thousands of civilians and displaced millions.