Witnesses told Reuters they watched dozens of Eritrean soldiers roll through the Tigrayan town of Adigrat in military trucks on Wednesday, the first reported sighting of Eritrean forces inside Ethiopian territory since fighting between Addis Ababa and a Tigrayan-led rebel alliance reignited on September 23. If confirmed, it would mark a dangerous new phase in a war that has already shattered diplomatic relations across the Horn of Africa.

The soldiers, identified by their distinctive off-white camouflage uniforms, were seen in two trucks passing through Adigrat, a town roughly 25 kilometers south of the Eritrean border, according to Al Jazeera's account of the Reuters report. Gebreigziabher Beyene, commander of the pro-government Tigray Peace Force, said the Eritrean army had entered Tigray "equipped with heavy weaponry" and accused Asmara of deliberately fighting on Ethiopian soil to keep the war off its own territory. Eritrea's information minister, Yemane Meskel, did not deny the claim, but accused Addis Ababa of inventing a "self-defense" narrative to justify what he called a war of aggression.

A week of diplomatic ruptures

The sighting comes days after Ethiopia and Eritrea severed relations entirely. Ethiopia's foreign ministry announced on October 1 that it was closing its embassy in Asmara and expelling 10 Eritrean diplomats, including the charge d'affaires, giving them 48 hours to leave the country and accusing Eritrea of "direct and indirect acts of hostility and belligerence." Eritrea responded in kind, with its foreign ministry saying it "has no option but to reciprocate... and sever all diplomatic ties with Ethiopia," according to Al-Monitor. Explosions, possibly from a drone strike, were also heard overnight in Addis Ababa around the same time.

Ethiopia accuses Eritrea, Sudan and Egypt of arming and sheltering the seven-group rebel alliance led by the Tigray People's Liberation Front; all three countries deny it. Eritrea, Somalia, Sudan and Egypt have since issued a joint declaration calling for a "political, peaceful solution," language Addis Ababa has read as a rebuke of its own policies. Ethiopia also declared an Egyptian diplomat persona non grata, prompting Cairo to expel an Ethiopian embassy official in return, and the African Union Commission has urged all sides to exercise maximum restraint.

The latest escalation traces back to September 23, when the TPLF-led alliance launched an offensive that shattered the 2022 Pretoria Agreement, the deal that ended Ethiopia's brutal 2020-2022 civil war, a conflict estimated to have killed around 600,000 people. The alliance briefly seized Tigray's capital, Mekelle, and its airport last month, but government-allied forces retook the city on October 3 and 4 after the TPLF withdrew, according to TimesLive, which cited three Reuters sources.

"This is a continuation of the previous war," TPLF chairman Debretsion Gebremichael said, vowing his forces would keep attacking and defending Tigray.

The reversal is not lost on regional analysts: Eritrea fought alongside Ethiopia's federal government against the TPLF during the 2020-2022 war. This time, Addis Ababa accuses its former ally of backing the very rebels it once helped crush, a shift fueled in part by Prime Minister Abiy Ahmed's renewed push for Ethiopian access to the Red Sea, a demand Eritrea and its neighbors have firmly resisted.

For now, the core facts remain unconfirmed by any government. Reuters said it could not independently verify the Adigrat sighting, and Addis Ababa has not commented on it. But with four countries' diplomats already expelled, a capital city rattled by explosions, and soldiers reportedly crossing an international border, analysts and the African Union alike are warning that the Horn of Africa is edging toward a wider war than the one that just reignited it.