Nearly four years after a peace deal ended one of this century’s deadliest wars, fighting has broken out in Ethiopia's northern Tigray region once again.
But the battle lines have shifted this time, with former enemies joining forces against Prime Minister Abiy Ahmed and Tigrayan factions fighting on opposing sides.
The Tigrayan People's Liberation Front (TPLF) and Tigray Defence Forces launched a major offensive on September 23, seizing the airports at Mekelle, Aksum and Shire.
Federal forces and allied fighters counter-attacked, entering the region's capital Mekelle on Saturday and declaring full control of the city by the following day.
The TPLF acknowledged its retreat in a statement on Sunday, saying its regional government would be “temporarily moved out of Mekelle and operate from somewhere else”.
However, the war is not over. Humanitarian sources reported air strikes and artillery exchanges overnight into Monday. One aid bulletin said air attacks killed at least 17 people in the towns of Adwa and Sheraro.
Addis Ababa accuses Egypt, Eritrea and the Sudanese Armed Forces (SAF) of backing the rebellion. All three deny it but their quarrels with Ethiopia threaten to turn an unfinished domestic conflict into a wider regional confrontation.
What lies behind the conflict?
Tigray is Ethiopia’s northernmost region, bordering Eritrea and Sudan. Its population is predominantly Tigrayan and speaks Tigrinya, a language also spoken across the Eritrean border.
Ethiopia’s regions are organised largely around ethnic and linguistic identities, with their own administrations and substantial autonomy.
This “ethnic federalism” recognises the country’s diversity, but makes disputes over boundaries, political representation and central authority particularly combustible.
The TPLF dominated Ethiopia’s ruling coalition for nearly three decades before Mr Abiy came to power in 2018. Its leaders retreated to Tigray as relations with the federal government unravelled after they refused to join Mr Abiy's new party.
Civil war broke out in November 2020 after Tigrayan forces attacked federal army bases, an operation they described as pre-emptive. Ethiopia’s army fought alongside forces from Tigray's neighbouring Amhara region, Fano militias and Eritrean troops. The fighting spread to Amhara and Afar, killing hundreds of thousands through violence, hunger and the collapse of essential services.
An African Union-brokered agreement signed in Pretoria in November 2022 stopped the major fighting. The TPLF promised to disarm, and Tigray was to receive an interim administration acceptable to both sides.
But the settlement did not address territorial disputes and notably excluded Eritrea, a major participant in the war.
Why has fighting resumed?
The status of contested territory that Amhara forces had taken control of remained unresolved, leaving many Tigrayans in displacement camps. The TPLF regarded the Pretoria settlement as lopsided, while the federal government accused it of failing to disarm as per the terms of the deal.
A split within the TPLF further weakened the peace. Getachew Reda, a former party spokesman who led the postwar interim Tigray administration, favoured engagement with Addis Ababa. An opposing faction led by Debretsion Gebremichael, who had previously led Tigray through the 2020-22 war, accused his administration of compromising Tigrayan interests.
The TPLF expelled Mr Getachew in 2024 and pushed him out of the interim administration in early 2025. In April 2025, Mr Abiy made him an adviser with ministerial rank in the federal government.
The TPLF then revived Tigray’s prewar regional council and installed its chairman, Mr Debretsion, as regional president. The Addis Ababa-backed interim government rejected the takeover as illegal.
The TPLF also stepped up military conscription and signalled it wanted to remove Mr Abiy. Addis Ababa, already withholding federal funds and restricting fuel to Tigray, began occasional drone strikes in the region.
On September 20, seven organisations formed the Ethiopian Peoples’ Forces Alliance for Survival and pledged to overthrow Mr Abiy.
Two days later, the government launched a major drone attack against an apparent concentration of Tigrayan forces.
While the TPLF describes its campaign as defensive, the International Crisis Group attributes the large-scale ground offensive primarily to the TPLF and its allies.
Who is fighting whom?
The federal army is supported by allied formations, including the Tigray Peace Forces, an anti-TPLF Tigrayan armed group.
Its participation makes the previous war's “Ethiopia against Tigray” tagline an inadequate description this time around.
The opposition alliance includes the TPLF, Amhara Fano National Movement, Oromo Liberation Army, Ogaden National Liberation Front, Afar Revolutionary Democratic Unity Front, Benishangul Peoples’ Liberation Movement and Gumuz Peoples’ Democratic Movement.
The Amhara Fano National Movement represents the biggest reversal in positions. Its fighters helped Mr Abiy against the TPLF during the previous war, then began their own insurgency against Addis Ababa in August 2023 after his government moved to dismantle their regional security forces. Many Amharas feared the reform would leave them vulnerable and jeopardise their hold on territory seized from Tigray.
So, the new alliance is based less on a shared blueprint for Ethiopia and more on facing a common opponent. But co-operation does not erase rival territorial claims among its members, nor guarantee agreement over what follows Mr Abiy's government.
The alliance’s sharpest fault line is over territory in western and southern Tigray, which Amhara forces seized during the previous war. Tigrayan leaders demand its return, while Amharas claim it as historically theirs.
Eritrea and TPLF make up
Eritrea's original intervention grew out of decades of hostility towards the TPLF, which led Ethiopia during the 1998-2000 border war. The two governments then backed each other's opponents for years. That makes Eritrea's new alignment with the TPLF all the more striking.
Mr Abiy's rapprochement with Eritrea in 2018 gave both an opportunity to confront their shared enemy. Asmara wanted the TPLF decisively defeated and resented the Pretoria deal for stopping short of that.
Relations subsequently soured over Ethiopia’s pursuit of access to the Red Sea. Eritrea fears Ethiopian designs on its Assab port, although Mr Abiy says he will seek access peacefully.
Crisis Group says Eritrea is now “quietly aligned with its former enemy the TPLF”. Diplomats and analysts told Reuters that Mr Isaias is giving the rebels access to the coast. In the last war, Tigray was cut off on all sides.
Eritrea denies helping the rebels. However, ties broke down last Thursday after Ethiopia closed its embassy in Asmara and expelled 10 Eritrean diplomats. Eritrea responded cutting diplomatic relations.
Over the past few years, Eritrean officials have increasingly portrayed the Addis Ababa government, rather than the TPLF, as the principal threat to their security.
Last week, Eritrea’s Foreign Ministry accused Ethiopia of seeking its ports and coastal territory through force, and of training armed groups to destabilise its government.
Where do Sudan and Egypt stand?
Crisis Group says SAF hosts thousands of Tigrayan fighters, many of whom have fought alongside it against the paramilitary Rapid Support Forces. It also reports alleged Ethiopian assistance to the RSF, which Addis Ababa denies.
Ethiopia’s army chief accused Sudan, Egypt and other powers of supplying the rebels in late September, without presenting public evidence. Egyptian Foreign Minister Badr Abdelatty rejected the claim, saying Cairo had nothing to do with events inside Ethiopia.
The Nile dispute remains central to their rivalry. On Monday, President Abdel Fattah El Sisi reaffirmed Egypt’s water rights and pledged to defend them through international law.
A day earlier, he hosted Eritrean, Sudanese and Somali leaders in New Alamein. Their declaration rejected unilateral measures affecting Egyptian and Sudanese water use, reserved Red Sea governance for coastal states, and opposed recognition of Somaliland, Ethiopia’s prospective sea-access partner.
The summit demonstrated shared objections to Ethiopian policies, not evidence that its participants are arming rebels. Ethiopia's renewed war grew from an unfinished peace. Its neighbours’ rivalries now make it harder to contain.
