Ethiopia's new rebel war redraws alliances across the Horn of Africa

Ethiopia and Eritrea have cut diplomatic ties as a new rebel offensive grips northern Ethiopia, putting two countries that fought together during the last Tigray war on opposing sides. Ethiopia accuses its neighbour of supporting a new anti-government alliance.

Ethiopia announced on Thursday that it was closing its embassy in the Eritrean capital, Asmara, and expelling 10 Eritrean diplomats suspected of activities posing "a direct threat to national security".

Citing "hostile and warlike acts", Addis Ababa gave the diplomats 48 hours to leave.

"Eritrea has no option but to reciprocate in kind and sever all diplomatic ties with Ethiopia," the Eritrean foreign ministry said hours later, describing the expulsion of its ambassador as "astounding".

Ethiopian federal forces are battling an alliance of armed groups that includes the Tigray People's Liberation Front ( TPLF ) and the Amhara Fano National Movement , whose fighters backed the federal government against the TPLF during the last Tigray war.

Fighting is under way across parts of Tigray and the neighbouring regions of Afar and Amhara, in the most serious hostilities since a peace agreement ended the Tigray war in 2022.

Ethiopia had already accused Eritrea , Sudan and Egypt on Sunday of supporting the offensive launched on 22 September. Eritrea denies the accusation.

Ethiopia accuses Sudan, Eritrea of backing Tigray forces as fighting escalates

"The dispute between the two countries goes back a very long way – for months and months, Asmara and Addis Ababa have regularly traded insults," Horn of Africa specialist René Lefort told RFI.

The immediate trigger for Ethiopia's action, he added, was its accusation that Eritrea was directly and indirectly helping the armed rebellion now engaged in large-scale fighting with the federal government.

The question now is whether the escalation stops there or the authorities in Addis Ababa go further, Lefort said.

The split marks a dramatic reversal from 2018, when Ethiopian Prime Minister Abiy Ahmed restored ties with Eritrea after two decades of hostility.

The two countries had fought a war over their border from 1998 to 2000. Their reconciliation helped earn Abiy the Nobel Peace Prize in 2019.

Eritrean troops later fought alongside Ethiopian federal forces against the TPLF during the 2020-2022 Tigray war .

This time, the two countries are on opposing sides.

Relations have also deteriorated over Ethiopia's push for direct access to the Red Sea . The country lost its coastline when Eritrea became independent in 1993.

Sea access is essential to the country's long-term economic and security interests, Abiy has argued, while Eritrea accuses his government of having ambitions over Eritrean ports.

EU calls for 'de-escalation' as Tigray rebels clash with Ethiopian forces

Earlier this week explosions hit the headquarters of the Ethiopian National Defence Force in western Addis Ababa. The capital had never previously been targeted by military action – not even during the Tigray war.

No link has been established between the blasts and the diplomatic rupture with Eritrea.

The attack has been blamed on a rebel alliance known as the Coalition for Survival, but none of its armed groups has claimed it, RFI's correspondent in Ethiopia reported. A diplomatic source nonetheless considers their involvement very likely.

"We are at war, so our only aim is to damage the regime's infrastructure," a coalition member said when questioned about the explosions.

Ethiopia's national intelligence service had banned all drone flights over and around Addis Ababa the day before the explosions. Last week, a drone struck the Bishoftu air force base, 40 kilometres from the capital, the conflict-monitoring network Acled said.

Focusing attacks on military targets is an "effective strategy", an analyst who asked not to be named told RFI. If the rebels are behind the blasts, they "spare civilians" and "do not unnecessarily risk the lives of their fighters".

Striking the enemy on its own ground also sends "a message" and makes it "more vulnerable", the analyst added.

Seven of Ethiopia's armed groups announce anti-government alliance

The TPLF joined six other armed movements in September to form the Coalition for Survival, whose stated objective is to remove Abiy's government from power.

Reports say federal forces and their allies appear to have made gains in southern Tigray and are advancing towards the regional capital, Mekelle.

At least 52 civilians were killed during three days of intense fighting in the town of Alamata, a doctor told the BBC earlier this week.

The TPLF has also been fighting in neighbouring Afar, which lies along Ethiopia's important transport corridor to Djibouti and the sea. Tens of thousands of people are estimated to have fled their homes there.

Eritrean soldiers have been involved on the front lines, a pro-government militia commander fighting in Tigray told the BBC , which has not independently verified the claim.

For now, Eritrean President Isaias Afwerki is reportedly giving the rebels access through his country to the coast and the outside world. During the previous Tigray war, Tigrayan forces were cut off on all sides.

Rebel forces in Ethiopia's Tigray state condemn army drone strikes

Ethiopia's military chief has accused Sudan and Egypt of supporting Eritrean operations inside Ethiopia. Both countries deny any meddling.

Egypt and Sudan are also at odds with Ethiopia over the Grand Ethiopian Renaissance Dam on the Blue Nile . Both are downstream and fear the dam could threaten their water supplies, while Ethiopia sees it as crucial to its economic development.

Drone activity and air strikes are putting civilians, vital infrastructure and aid operations at risk, while insecurity and road closures are restricting relief efforts in northern Ethiopia, United Nations spokesman Stéphane Dujarric warned on Thursday.

Sudan's own war has added another layer to the regional tensions. Its army has been fighting the paramilitary Rapid Support Forces for three years, with some Tigrayan forces fighting alongside it.

Several diplomats told Reuters that Khartoum also hosted meetings that led to the creation of the new Ethiopian rebel alliance.

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