The United States government has cautioned Ethiopia's warring parties after violence escalated this week with the aerial strikes in Mekelle, the capital of the troubled northern Tigray region.
Washington, which has threatened sanctions on peace spoilers, said the parties must lay down arms and choose dialogue.
"We have seen the credible reports of attacks in and around Mekele. The United States condemns the continuing escalation of violence, putting civilians in harm’s way" State Department spokesman Ned Price tweeted on Wednesday.
The US had threatened to impose sanctions if the parties to the Tigray conflict fail to reach a negotiated settlement to end the nearly year-long bloody civil war that killed tens of thousands of people and displaced millions.
The US official urged the warring factions to immediately cease hostilities as the conflict between the government and Tigray rebels intensified.
"The government of Ethiopia and the Tigray People's Liberation Front (TPLF) must end hostilities and begin talks now," Mr Price said.
The call comes after Ethiopia carried out airstrikes in Mekelle this week as part of its new major offensives to crush the TPLF, the horn nation's once-dominant ruling party.
The airstrikes have so far killed at least three children and injured 16 others including a pregnant woman.
On Thursday, the Ethiopian Air Force launched its fourth bombardment this week in a campaign it says is targeting rebel facilities.
The Ethiopian government spokesman Legesse Tulu confirmed that an airstrike was conducted on Thursday afternoon.
He said the target was a facility was a former army base which now serves as a training centre for the TPLF forces.
"Abiy Ahmed's Air Force made three attempts to strike targets in Mekelle this [Thursday] afternoon. Our air defence forces have so far managed to protect our people," Getachew Reda, the TPLF spokesman wrote on his Twitter page.
But federal official Selamawit Kassa, state minister of government communication services, disputed Getachew's claim, telling AFP "it was a successful mission".
'Decisive and final' offensive
About two weeks ago Ethiopia PM Abiy Ahmed's government launched what it said was a "decisive and final" offensive in a bid to push back TPLF forces from larger parts of the Amhara region which they have taken control of in recent few months.
On Monday Ethiopia's air force launched two strikes in Tigray's capital Mekele that the UN said killed three children and wounded several other people.
And on Wednesday it bombed TPLF weapons caches in Mekele and in the town of Agbe, which lies about 80 kilometres (50 miles) to the west.
A hospital official told AFP that Wednesday's strike in Mekele injured at least eight people, including a pregnant woman.
TPLF spokesman Kindeya Gebrehiwot told AFP there were no casualties from Thursday's strike.
The air strikes come amid reports of heavy fighting in the Amhara region south of Tigray, where the TPLF launched an offensive in July.
On Wednesday Getachew claimed on Twitter that TPLF fighters had taken control of at least two new towns in the region, putting the cities of Kombolcha and nearby Dessie -- where tens of thousands have sought refuge from the rebel advance -- "within artillery range".
Much of northern Ethiopia is under a communications blackout and access for journalists is restricted, making battlefield claims difficult to independently verify.
Dessie residents on Thursday reported a heavy military presence in the area as displaced civilians from conflict-hit towns farther north continued to arrive.
"People are coming to Dessie from Hayk [town] while others are leaving in fear of military conflict," said one resident, speaking on condition of anonymity to protect relatives trapped in TPLF-controlled areas.
"Some businesses are shut down. The city is relatively calm today in comparison to what has been observed in the past three days."
Government officials have issued multiple calls in recent months for mass mobilisation to fight the TPLF, and diplomats estimate tens of thousands of people have enlisted.
Amhara regional president Yilkal Kefale called Thursday for armed Amharas to converge on Dessie to defend it.
"It is high time that the Ethiopian people must stand in unison in order to eliminate its common enemy," he said.