Forces of Ethiopia's Tigray People's Liberation Front (TPLF)
have destroyed an airport in the ancient town of Axum, state-affiliated media said on Monday, as advancing federal troops gave them a 72-hour ultimatum to surrender.
Prime Minister Abiy Ahmed has told the TPLF, which had been ruling the mountainous northern zone of 5 million people, to lay down their arms by Wednesday or face a final assault on the regional capital Mekelle.
TPLF leader Debretsion Gebremichael told Reuters that threat was a cover for government forces to regroup after what he described as defeats on three fronts.
There was no immediate response from either side to the other's latest comments, and Reuters could not confirm their statements. Claims by all sides are hard to verify because phone and internet communication has been down.
Hundreds, possibly thousands, have been killed in fighting and air strikes that erupted on Nov. 4, sending about 40,000 refugees into neighbouring Sudan. The conflict has spread beyond Tigray, with the TPLF firing rockets into both neighbouring Amhara region and across the border to Eritrea.
International appeals for mediation, from the United Nations and around Africa and Europe, have so far not gained traction.
Fana broadcaster said TPLF troops had destroyed the airport serving the town of Axum, which lies northwest of Mekelle and is a popular tourist draw and UNESCO World Heritage site.
Axum's history and ruins, including fourth century obelisks when the Axumite Empire was at its height, gives Ethiopia its claim to be one of the world's oldest centres of Christianity.
Legend says it was once home to the Queen of Sheba and that an Axum church housed the Ark of the Covenant.
The United Nations' humanitarian coordinator for Ethiopia, Catherine Sozi, urged safety guarantees for aid workers, Mekelle's more than half a million inhabitants, and their health, school and water systems.
Abiy's government has repeatedly said it is only targeting TPLF leaders and facilities to restore law and order after they rose up against federal troops. It denies hitting civilians.
"Our women and men in uniform have shown great care to protect civilians from harm during the law enforcement operation they have carried out in Tigray so far," its taskforce for the Tigray conflict said on Monday.
The TPLF says Abiy has "invaded" their region in order to dominate them and is inflicting "merciless" damage on Tigrayans.
"We are people of principle and are ready to die in defence of our right to administer our region," TPLF leader Debretsion added in a text message to Reuters on Monday.