War has returned to Ethiopia's Tigray region, and the federal government now holds its capital. Federal forces, fighting alongside a group called the Tigray Peace Forces, retook Mekelle after first capturing its airport, Al Jazeera, the BBC and Africanews reported. The Tigray People's Liberation Front, or TPLF, which had controlled the city, said it had "temporarily moved out."

The latest fighting began on Sept. 23, when seven armed groups formed an alliance against Prime Minister Abiy Ahmed's government, according to Al Jazeera. That move shattered a 2022 peace deal that ended an earlier war.

The conflict has quickly spread beyond Ethiopia's borders. Ethiopia accuses neighboring Eritrea, Sudan and Egypt of backing its enemies. Sudan and Egypt deny it. Eritrea has cut ties with Ethiopia. Egyptian President Abdel Fattah el-Sisi spoke about the crisis at an African Union summit in El-Alamein, and the U.S. State Department has urged restraint.

Here is the background. Tigray's war from 2020 to 2022 was one of the deadliest conflicts of this century. Hundreds of thousands of people died from fighting, hunger and lack of medical care. Peace talks in Pretoria, South Africa, ended that war in November 2022, but tensions over land, power and disarmament never fully went away.

Mekelle is home to about half a million people. During the last war, the city was cut off from banking, phone service and fuel for long stretches, and aid groups warned of famine. Those fears are rising again.

Ethiopia is Africa's second most populous country, with about 130 million people. Instability there can ripple across the Horn of Africa, a region already strained by war in Sudan.

What we know: Federal forces hold Mekelle, and the TPLF says it has pulled out for now.
What we don't: How many people have been killed or displaced, and whether the war will widen.