The strike on Wednesday hit Mai Aini refugee camp near the southern Tigrayan town of Mai Tsebri, the UN said.
"Three Eritrean refugees, two of them children, were killed," the United Nations High Commission for Refugees (UNHCR) High Commissioner Filippo Grandi said in a statement, adding four other refugees were injured.
Government spokesperson Legesse Tulu and military spokesperson Getnet Adane did not immediately respond to requests for comment. The government has previously denied targeting civilians.
On December 30, the United Nations Office for the Coordination of Humanitarian Affairs said that dozens of civilians had been reported killed in southern Tigray in air strikes that week in what it described as "the most intense attacks and highest casualties reported since October".
The 14-month-old war in northern Ethiopia between the federal government and the Tigray People's Liberation Front (TPLF), who used to dominate Ethiopian politics, has killed thousands of civilians and displaced millions.
Last month, Tigrayans forces withdrew from neighbouring regions, which they had invaded in July. Air strikes on the Tigray region have continued and the United Nations says no humanitarian aid is able to enter the region.
There are 150,000 Eritrean refugees living in Ethiopia and some have been violently targeted by belligerents on both sides of the conflict and cut from aid for months at a time.
A Reuters investigation in November revealed that Eritrean refugees had endured targeted killings, gang rapes and looting by both the TPLF and Eritrean forces, who entered the conflict on the side of the Ethiopian federal government.Â
