Seven Ethiopian armed groups, including longstanding enemies who fought on opposite sides of a 2020-2022 civil war, said they have formed an alliance aimed at overthrowing Prime Minister Abiy Ahmed's government.

The announcement of the Ethiopian Peoples' Forces Alliance for Survival brought together a geographically and ethnically diverse body of groups ranging from Tigray in the north to Somali Region in the south. Some remain at loggerheads with other members over territory and other issues.

Spokespeople for Abiy and the federal government did not immediately respond to requests for comment. Last month, after reports of a possible coalition of armed groups, an adviser to Abiy said any such formation would seek to wreak havoc but would not be able to overthrow the federal government.

The new alliance, announced late on Sunday, includes the Tigray People's Liberation Front (TPLF) and the Amhara Fano National Movement. Fano, a coalition of armed groups from the Amhara region, fought in support of the federal government against the TPLF during the 2020-2022 Tigray war, which resulted in hundreds of thousands of deaths and was marked by ethnically driven atrocities.

Fano subsequently rose up against the federal government in a conflict that has killed thousands in Amhara since 2023.

Many of the groups have accused the government of centralising power and marginalising the regions. The government says it has launched a national dialogue meant to address longstanding political divisions and internal conflicts. 

"We, the peoples' forces concerned with the survival of Ethiopia's peoples, bear the historic responsibility of overthrowing this regime," said the statement read out by Fano leader Zemene Kassie and broadcast on Tigrayan television.

The announcement of the alliance, which also includes groups from the Oromia, Afar and Benishangul-Gumuz regions, follows reported skirmishes between federal and Tigrayan forces.

In May, the TPLF reasserted control over the region's political administration in violation of the 2022 peace deal that ended the Tigray war after accusing the federal government of failing to uphold the agreement. 

The Ethiopian military has carried out several drone strikes against Tigrayan forces in recent months, according to data from the Armed Conflict Location & Event Data project.

The federal government has not commented on the reported strikes, but the military said last week that nearly 300 Tigrayan fighters had surrendered to it. 

Ethiopia has also accused its neighbour and historic adversary Eritrea of supporting insurgent groups, including the TPLF and Fano. Eritrea has denied this.