Ethiopian federal forces and allied militia have entered Adwa, a strategic town in Tigray near the Eritrean border, after fighters of the Tigray People's Liberation Front (TPLF, the former regional ruling party turned rebel group) withdrew without a fight, according to residents. The advance follows the recapture of the regional capital Mekelle, where Ethiopian Airlines has resumed flights, while Addis Ababa accuses Eritrea of backing the rebels and sending troops into Tigray, which Asmara denies and has asked the UN to address. It matters because it raises fears of a return to wider war between the two neighbours, which fought a deadly border conflict in 1998-2000, and UN Secretary-General António Guterres has urged all sides to end hostilities and resume dialogue.