Ethiopia’s Prime Minister Abiy Ahmed says government forces are now “fully in control” of the regional capital of the northern Tigray region.
The army earlier entered Mekelle as it stepped up its offensive against the Tigray People’s Liberation Front.
The leader of the TPLF told Reuters it would continue to “defend our right to self-determination” and “fight these invaders to the last”.
Hundreds have been killed and thousands displaced in the conflict.
It began earlier this month after Mr Abiy announced an operation against the TPLF, the regional party, accusing it of attacking the Ethiopian army’s northern command HQ in Mekelle.
In a statement on Twitter, Mr Abiy said the army was in full control and that this “marks the completion of the [military’s] last phase”.
“I am pleased to share that we have completed and ceased the military operations in the Tigray region,” he said.
The army had released thousands of soldiers taken by the TPLF and was in control of the airport and regional offices, Mr Abiy said, adding that the operation had been carried out with “due care for citizens”.
There have been fears for the 500,000 people living in the city.
Mr Abiy said: “We now have ahead of us the critical task of rebuilding what has been destroyed… [and] returning those who have fled.”
Details of the fighting are hard to confirm because all phone, mobile and internet communications with the Tigray region have been cut.
In a text message to Reuters, TPLF leader Debretsion Gebremichael did not directly comment on the situation on the ground, but said of the government forces: “Their brutality can only add [to] our resolve to fight these invaders to the last.”
He added: “This is about defending our right to self-determination.”
An earlier TPLF statement, reported by AFP, urged “the international community to condemn the artillery and warplane attacks and massacres being committed”.
It also accused the Eritrean government of involvement in the attack on Mekelle.
Analysts say the TPLF could now be preparing to return to the mountains to launch a guerrilla war against the federal government.
The UN had warned of possible war crimes if the Ethiopian army attacked Mekelle.