It is the third bombing in just a few days, a sharp escalation of the conflict that has been going on for almost a year between the country's government forces and the rebels TPLF (Tigrean Liberation Front).
A government spokesman has confirmed the attack.
The latest attack was carried out in Agebe, 80 kilometers west of the region's capital Mekele on Wednesday.
The target was a military training camp and camp for heavy artillery, says Legesse Tulu, who is a spokesman for the Ethiopian government.
Earlier in the day, an airstrike was carried out on Mekele.
The Tigray Civil War escalated on Monday when the Ethiopian military bombed Mekele.
After first dismissing the information about airstrikes on the state capital as an "absolute lie", the government admitted via state media that the air force on Monday had attacked media and communication equipment belonging to TPLF.
In the latest airstrike on Wednesday, nine civilians, including a five-year-old child, were injured and cared for at Ayder Referral Hospital, according to Tigrai Television, which is controlled by the TFLP.