Formal talks after two years of war between the Ethiopian federal forces and the northern region of Tigray opened in South Africa on Tuesday.

The African Union, as mediator, aims to broker an end to the conflict, which has killed thousands and displaced millions, putting a large section of the population on the brink of famine.

The discussions, which will continue until Sunday, are the highest-level effort yet aimed at bringing the violence to an end.

What are the latest developments?

South Africa hopes "the talks will proceed constructively and result in a successful outcome that leads to peace for all the people of our dear sister country," said Vincent Magwenya, spokesperson for South Africa's President Cyril Ramaphosa.

Ethiopia's national security adviser Redwan Hussein is negotiating on behalf of Addis Ababa, while Tigray's interests are represented by military spokesperson Getachew Reda and a member of the Tigrayan central command, Tsadkan Gebretensae.

AU Commission chair Moussa Faki Mahamat said he was "encouraged by the early demonstration of commitment to peace by the parties" and reiterated the AU's continued support for a process "to silence the guns towards a united, stable, peaceful and resilient Ethiopia."

The talks begin as Ethiopian government forces, supported by troops from neighboring Eritrea and Amhara special forces, have started to take some urban parts of Tigray province. Intensified fighting in the past two months has raised fears about the possibility of mounting civilian casualties. 

The discussions are being facilitated by Nigeria's former president Olusegun Obasanjo and supported by Kenya's former leader Uhuru Kenyatta and South Africa's ex-vice president Phumzile Mlambo-Ngcuka. 

United Nations and the United States representatives are also participating as observers, the African Union said.

"We are looking very eagerly at [South Africa] to the talks. That's the only way forward," Filippo Grandi, the United Nations High Commissioner for Refugees, said at a press conference in the Kenyan capital, Nairobi. "If the parties do not really engage meaningfully in a negotiated solution, we'll be in this situation forever."

US Secretary of State Antony Blinken urged the parties to engage seriously and agree an immediate truce. "These talks represent the most promising way to achieve lasting peace and prosperity for all Ethiopians," he said in a statement.

What has been happening in Ethiopia?

The invitation comes more than a month after intense fighting resumed, bringing to an end a March truce that promised hope of ending the war.

War broke out when Prime Minister Abiy Ahmed sent troops to topple the Tigray region's ruling TPLF. He accused the party — which dominated Ethiopia's ruling coalition for decades before Abiy took power in 2018 — of attacking federal army bases.

The conflict led to a humanitarian crisis in Tigray with millions of people left desperately short of food.

The fresh violence has also drawn Eritrean troops, allied with the Ethiopian government, back into the conflict. Eritrea, which signed a peace deal with Abiy that helped him win the Nobel Peace Prize, rejects allegations that its soldiers committed some of the worst atrocities in the conflict.

This article has been updated to include reactions to the commencement of the peace talks.

rc,kh/aw,ck (AP, AFP, Reuters)