The official, who asked not to be identified, spoke on Thursday as medical workers and aid agencies were still scrambling to evacuate dozens of seriously injured patients from the town of Togoga to the regional capital Mekelle, about 25 km to the southeast, two days after the bombing.

He said at least 68 patients had reached hospitals in Mekelle but the total number injured was likely more than 100.

Nathalia Estevam Fraga, head of the International Committee of the Red Cross (ICRC) in Mekelle, said getting wounded patients to a surgical theatre "was a matter of life and death" for some of them.

The attack was one of the deadliest reported incidents in months in a region where the government had said most major fighting ended last year. Residents have reported increased clashes this week in towns north of regional capital Mekelle.

In the military's first account of the incident, Colonel Getnet Adane, Ethiopia's military spokesman, said only combatants, not civilians, had been hit. He said the full death toll was still being gathered.

Getnet told Reuters that the combatants had been dressed in civilian clothes and had gathered in the town to commemorate the anniversary of the bombing of another town in Tigray, Hawzen, in 1988. That attack, by Ethiopia's then-ruling Communist leaders, killed hundreds of people and is widely commemorated in Tigray.

However, the health official involved in the response said it was clear the victims were not combatants: "Based on eye witnesses and the health teams we sent, the dead are civilians," the official said. "It was in the middle of town and on market day."

A resident of the town told Reuters on Wednesday that the strike hit a market at around 1 p.m. That resident also said that her 2-year-old daughter had been injured in the attack.

The military has been battling forces loyal to the Tigray People's Liberation Front (TPLF), the region's former ruling party, since November. Fighting has displaced 2 million people, and the United Nations has warned of famine conditions in parts of the region.

The air strike took place as Ethiopian officials counted ballots from national and regional parliamentary elections held this week in seven of the nation's 10 regions.

No voting was held in Tigray, and security concerns and problems with ballot papers also delayed voting in two other regions.

Asked about children injured in Tuesday's attack, Getnet said the TPLF uses propaganda and is known for faking injuries. He also said that doctors quoted by the media are not "real doctors".

A TPLF spokesman could not immediately be reached for comment. Previously, Getnet had declined to confirm or deny the incident, saying air strikes were a common military tactic and that government forces do not target civilians.