Clashes near Sheraro mark one of the most serious threats yet to the fragile 2022 Pretoria peace deal.

Fighting has broken out in western Tigray, in one of the most serious breaches yet of the three-year-old peace deal between Ethiopia’s federal government and fighters in the northern region.

Tigray’s regional government said in a statement from Mekelle, the Tigrayan capital, that federal forces opened the assault at dawn on Saturday, advancing from the direction of Sheraro, near the Sudanese border.

Abraham Belay, a government minister who led Tigray’s transitional government during the war, confirmed the clashes but accused Tigray People’s Liberation Front (TPLF) chairman Debretsion Gebremichael’s forces of starting them.

“Enough war! Let us resolve our differences through dialogue,” he said in a post on Facebook.

The fighting follows months of deteriorating relations between Addis Ababa and the TPLF, the party that ruled Ethiopia for nearly three decades before Prime Minister Abiy Ahmed came to power in 2018.

Both sides have accused each other of failing to implement the provisions of the 2022 peace agreement.

Tigrayan authorities said Ethiopia’s ruling Prosperity Party has waged a long blockade and drone campaign against the region, adding that this had now escalated into full-scale war.

The regional government urged Tigrayan forces, civil society and religious institutions to prepare for a struggle it called one of national survival, using the slogan “No to National Destruction”.

Getachew Reda, a former TPLF spokesman who now advises Abiy, separately urged the Tigray Defence Forces commanders to abandon Debretsion, accusing him of relying on Eritrea and Amhara’s Fano militia to force his way back to power.

Reda and Redwan Hussein, Ethiopia’s intelligence chief, who signed the Pretoria deal for TPLF and the federal government respectively in 2022, co-wrote an Al Jazeera op-ed in June warning that war was imminent.

Kjetil Tronvoll, an Ethiopia specialist at Oslo New University College, told Al Jazeera that the fighting marked the “most serious incident” since the 2022 peace deal. The deal, Tronvoll added, halted the war between the two parties but left “the core reasons of conflict between Mekelle and Addis” unresolved.

In the days running up to the armed clashes, Ethiopian state media ran a campaign accusing Debretsion by name of rallying Tigrayans toward war.

The fighting caps months of escalating confrontation since the Pretoria Agreement of November 2022, which ended a war that began two years earlier and killed hundreds of thousands, but left unresolved deeper disputes over disarmament and the TPLF’s legal status.

In June, the United States imposed visa restrictions on what it said were TPLF “hardliners” accused of blocking peace. The TPLF described it as being based on an “incomplete and imbalanced” picture of the standoff.

By mid-July, TPLF had declared the Pretoria agreement “effectively dead”, even as US Ambassador Ervin Massinga travelled to Mekelle to try to preserve the deal.

Faisal Roble, a regional analyst, told Al Jazeera that the beginning of the fighting was a sign that efforts to resolve the dispute between the parties by the US had not succeeded.

“Without a powerful international intervention,” he said, “we could be heading to a much larger war.”