PRETORIA, Nov 2 (Reuters) - The parties in the conflict in Ethiopia's northern region of Tigray have agreed to cease hostilities, a dramatic diplomatic breakthrough two years into a war that has killed thousands, displaced millions and left hundreds of thousands facing famine.The war, which broke out in November 2020, pits regional forces from Tigray against Ethiopia's federal army and its allies, who include forces from other regions and from neighbouring Eritrea.African Union mediator Olusegun Obasanjo, welcoming delegates from the government and the Tigray forces to a signing ceremony on Wednesday in the South African capital Pretoria, said the agreement would allow humanitarian supplies to Tigray to be restored.Obasanjo, a former Nigerian president who has been leading the African Union's mediation team, said the implementation of the agreement would be supervised and monitored by a high-level African Union panel.The war stems from a catastrophic breakdown in relations between the Tigray People's Liberation Front, a guerrilla movement turned political party which dominated Ethiopia for 27 years, and Abiy, who was once part of their ruling coalition but whose appointment in 2018 ended the TPLF’s dominance."