An airstrike hit Mekelle, the capital of Ethiopia's northern Tigray region on Friday, which local media controlled by the breakaway authorities blamed on the federal government.
Tigrai Television showed images of damaged buildings and what appeared to be wounded people lying on the ground being attended to by medical personnel.
An aid organization confirmed that its staff in Mekelle had heard an explosion and anti-aircraft gunfire. A second humanitarian group in Mekelle confirmed hearing an explosion from the air strike.
Earlier on Friday, the Ethiopian government urged Tigrayan citizens in a statement to stay away from military and training facilities, saying the government intended to "take actions to target the military forces".
Government spokesperson Legesse Tulu did not respond to Reuters queries regarding the air strike.
The strike comes days after fighting resumed on the border of the Tigray and Amhara regions between the national government and forces from the Tigray region.
Both sides have blamed each other for breaking the four-month-old ceasefire between Prime Minister Abiy Ahmed's government and the Tigray People's Liberation Front (TPLF), the party that controls Tigray.