Civilians in the capital of Ethiopia's Tigray region should "save themselves", a spokesman for the federal military has said, amid plans to surround Mekelle with tanks and warnings that the rebel stronghold could be shelled.
Colonel Dejene Tsegaye:
"We want to send a message to the public in Mekelle to save themselves from any artillery attacks and free themselves from the junta. After that, there will no mercy."
Prime Minister Abiy Ahmed's troops have taken a string of towns during aerial bombardments and ground fighting and now have their sights on the mountainous city, home to around half a million people.
It's the base of forces loyal to the region's ruling party, the Tigrayan People's Liberation Front, or TPLF.
But so far the TPLF has refused to back down, and says its soldiers are digging trenches and standing firm.
The conflict, triggered after Abiy accused the Tigrayan leaders of attacking the national army, has killed hundreds - possibly even thousands - and sent more than 30,000 refugees into neighboring Sudan.
TPLF leader Debretsion Gebremichael said his troops were resisting a push from the south whilst also fighting near a northern town which recently fell to the Ethiopian military.
With phone and internet communications down, claims by all sides are hard to verify.