The Ethiopian prime minister, who was awarded the Nobel Peace Prize in 2019, has rejected a request for peace talks as the conflict in Tigray deepens.

The Tigray President Debretsion Gebremichael wrote to the African Union (AU) last week to request talks.

But PM Abiy Ahmed said in a tweet that there would be no dialogue "until our efforts to ascertain the rule of law are achieved".

Hundreds have died since the conflict erupted last week.

Last Wednesday, Mr Abiy ordered a military offensive after an army base in Mekelle was taken over by forces loyal to the regional government of Tigray.

On Friday Mr Debretsion wrote to the AU asking for help. The chairman of the African Union Commission, Moussa Faki Mahamat, on Monday urged the federal government and the Tigray state authorities to engage in dialogue.

But on Tuesday Mr Ahmed said in a series of tweets that he wanted "to assure Ethiopians again" that there will be no dialogue until after rule of law is achieved.

He added: "Our law enforcement operations in Tigray are proceeding as planned: operations will cease as soon as the criminal junta is disarmed, legitimate administration in the region restored, and fugitives apprehended & brought to justice - all of them rapidly coming within reach."

How many people have died in the fighting?

It is difficult to say but reports indicate hundreds of deaths on both sides.

The national armed forces have killed 550 Tigrayan People's Liberation Front (TPLF) fighters, the state broadcaster in Ethiopia has said.

The claim has not been independently verified.

What other impact has the fighting had?

Residents have fled Tigray.

Officials in Sudan, which is on the border with the Tigray region, say at least 6,000 Ethiopians have arrived in the country.

The Sudanese authorities are preparing for a further 200,000 people to cross in the coming days.

Is anyone else involved in the fight?

On Tuesday, Mr Debretsion accused the neighbouring Eritrean government of launching attacks on the Tigrayan state.

The accusation was denied by both the Eritrean government and the Ethiopian national army.

What is behind the tension?

The leaders of Tigray dominated Ethiopia for many years but Mr Abiy curbed their influence after winning power in 2018 on the back of anti-government protests.

The situation began to deteriorate last year after Mr Abiy dissolved the ruling coalition.

It was made up of several ethnically based regional parties which he merged into a single, national party, the Prosperity Party, which the TPLF refused to join.

Tigrayan leaders say they have been unfairly targeted by purges and allegations of corruption, and say Mr Abiy is an illegitimate leader, because his mandate ran out when he postponed elections due to coronavirus

The simmering row boiled over in September after the TPLF defied the nationwide ban on elections, and held a vote which was declared illegal by the central government.

Why did Mr Abiy win the Nobel Peace Prize?

Mr Abiy won the prize in 2019 for his role in resolving the border conflict with Eritrea.

Ethiopia and Eritrea fought a bitter border war from 1998-2000, which killed tens of thousands of people.

Although a ceasefire was signed in 2000, the neighbours technically remained at war until July 2018, when Mr Abiy and Eritrea's President Isaias Afwerki signed a peace deal.