Rebel forces in Tigray have moved into regional capital Mekelle following the withdrawal of Ethiopian National Defence Force soldiers from the city.
The news - a major setback for the Ethiopian government - was confirmed by the national broadcaster this evening after fierce fighting surrounding Mekelle.
It marks a significant juncture in this eight-month-old conflict, which has been marked by multiple allegations of human rights abuses.
Alongside forces from neighbouring Eritrea, the Ethiopian military has held much of Tigray since last November.
Tensions between the national government led by Abiy Ahmed and the region's former leaders, the Tigrayan People's Liberation Front (TPLF) had been building for years after members of the TPLF left the governing coalition in 2018.
When a national military base in Tigray was attacked by rebel fighters, Mr Abiy seized the region and ousted its leaders in an operation that he declared "over" at the end of November.
On Monday night however, in another dramatic development, the Ethiopian government declared an immediate, unilateral ceasefire in Tigray.
A resident of Mekelle told Sky News that there were celebrations in the street after Ethiopian soldiers vacated the city in the afternoon.
"The TDF (Tigray Defence Force) hold the airport and we expect them in the city soon. Nobody is going to obey the curfew tonight," he said.
The head of UNICEF, Henrietta Fore, released a statement accusing Ethiopian soldiers of breaking international humanitarian law when they entered the organisation's office in Mekelle and "dismantled our VSAT equipment".
This equipment is used by UN personnel to communicate and connect to the internet in a region where all digital links have been cut by the Ethiopian government.
Soldiers may have been instructed to act in order to prevent pictures of their withdrawal from being broadcast.
The conflict has cost the lives of thousands and displaced approximately two million people. Civilians across the region have reported human rights abuses like mass killings and mass rapes.
The United Nations says 350,000 people are in danger of starving in a famine that is already under way.
Ethiopian troops reportedly abandoned a number of towns and cities, linked by the region's main highway including garrisons in Adigrat and Abiy Adiy.
Getachew Reda, a spokesman for the TPLF, said the TDF went on the offensive last week, capturing areas south of Mekelle along with several thousand Ethiopian troops.