ADDIS ABABA, Ethiopia — Ethiopia’s northern Tigray region is facing renewed fears of a full-scale conflict after Tigrayan forces seized control of airports and fighting spread into neighboring Afar and Amhara regions. Ethiopian Airlines suspended flights to Tigray after the airport takeovers. Federal officials and leaders of the Tigray People’s Liberation Front, the political party that controls the region, traded accusations over who initiated the latest violence. Getachew Reda, an adviser to Prime Minister Abiy Ahmed, said Tigrayan forces had launched an “all-out offensive” against federal government positions. Tigrayan authorities said their forces acted defensively in response to attacks by federal troops. The escalation follows months of disputes over territory, political authority and the implementation of a 2022 peace agreement that ended a two-year war. That conflict was among the world’s deadliest in recent years, with some estimates placing the death toll at roughly 600,000. The Armed Conflict Location and Event Data Project has reported that Ethiopian forces carried out drone strikes against Tigrayan fighters and TPLF officials in recent months. The strikes were concentrated in Mekelle, Tigray’s capital, and southern parts of the region. The TPLF announced Sunday that it had formed an alliance with six armed and political groups seeking to remove Abiy’s government and establish a transitional administration. In May, the party also reasserted control over Tigray’s regional government after years of rule by an interim administration established under the peace agreement. Tigray is Ethiopia’s northernmost region and borders Eritrea. Tigrayans represent about 6% of Ethiopia’s population but have played a major role in national politics. TPLF leader Meles Zenawi governed Ethiopia from 1991 until his death in 2012, after Tigrayan forces helped overthrow a military government. Alan Boswell, the International Crisis Group’s Horn of Africa director, said the federal government’s response could determine whether the confrontation remains limited or develops into another prolonged war. “The very big question next is how will the federal government respond?” Boswell said. “With total all out war? Or will we see a more measured response that tries to contain this and prevent a return to total war in Tigray?” The crisis is unfolding as Ethiopia faces armed conflict in Amhara and Oromia and as neighboring Sudan remains embroiled in a war that has lasted more than three years. Boswell warned that a wider Tigray conflict could also pull Eritrea into direct confrontation with Ethiopia because of Eritrea’s reported support for the TPLF. Mahmoud Ali Youssouf, chairperson of the African Union Commission, called for an immediate de-escalation and urged the parties to return to negotiations. U.S. Ambassador to Ethiopia Ervin J. Massinga condemned what he described as the TPLF’s decision to launch a large-scale offensive, calling it an “unwinnable fight.” The competing claims and limited independent information from the conflict zone have added to uncertainty for civilians who endured mass displacement, hunger and widespread destruction during the previous war. A return to sustained fighting could further strain humanitarian access and undermine the fragile political settlement reached in 2022.