Heavy shelling has been reported in Ethiopia's Tigray region on Thursday, 5 November, and more than 20 Ethiopian soldiers are thought to have been wounded amid growing ethnic clashes.
A humanitarian source in Tigray told Reuters two dozen soldiers had been treated at a clinic near the border with the Amhara region.
Ethiopia's Prime Minister Abiy Ahmed, who won the Nobel Peace Prize last year for solving a border dispute with neighbouring Eritrea, has refused to halt a military campaign in the Tigray region which could spiral into civil war.
Federal troops clashed with Tigrayan forces in the northern region on Wednesday after Abiy claimed government bases had been attacked by the Tigray People's Liberation Front (TPLF).
The TPLF was the dominant political force in Ethiopia for more than 20 years but fell out with Abiy when he came to power in 2018.
The US Secretary of State Mike Pompeo backed Abiy in a tweet on Wednesday.
Tensions between Addis Ababa and the TPLF have been escalating since September when Tigray held regional elections in defiance of the federal government.
Ethiopia is now in danger of collapsing into an ethnic civil war in a similar way to Yugoslavia in the 1990s.
There have been numerous outbreaks of inter-tribal violence in the last year and at the weekend, gunmen killed 32 people and set fire to 20 houses in the west of the country.
The killings were blamed on a splinter group which has broken away from the Oromo Liberation Front.
The country is an ethnic mixture of different tribes - Amhara, Oromo, Tigrayan, Somali, Sidama, Gurage, Wolayta and several others.
Emperor Haile Selassie, an Amhara, was deposed by a socialist military junta, the Derg, in 1974 and they ruled until the early 1990s when they were overthrown by a rebel movement, the Ethiopian People's Revolutionary Democratic Front.
But most of the fighting was done by the TPLF, which was led by Meles Zenawi, who became Ethiopia’s President in 1991.
Zenawi and a Tigrayan clique ruled the country until his death in 2012 and helped turn the it around, from one of Africa’s basket cases to the continent’s most thriving economy.
He was succeeded by Hailemariam Desalegn, a Wolayta, who passed the baton on to Abiy, an Oromo, in 2018.
But as the power of the Tigrayans was reduced there was growing ethnic unrest, especially among the Oromo, who make up a third of the country’s population of 114 million.