Ethiopian and Sudanese forces have clashed at the disputed al-Fashaga border area following the alleged capture, execution and public display of the bodies of seven Sudanese soldiers and a civilian killed over the weekend.
Sudan said on Tuesday that it had recaptured parts of its territory that were being held by the Ethiopian army.
The al-Fashaga area is where the north-west of Ethiopia’s Amhara region meets Sudan’s breadbasket, Gedaref state.
It has been contested for decades but tensions escalated over the last year with regular skirmishes reported between the two countries.
Witnesses have told the BBC that Sudanese forces advanced and retook two settlements that were being occupied by Ethiopians along the disputed area.
Military planes could also be seen circling the contested area as the Sudanese assault continued.
Pictures on social media showed dozens of Ethiopian military vehicles destroyed, but these could not be immediately verified.
Sudan accused Ethiopian troops of capturing and executing seven of its soldiers, but Addis Ababa has denied the allegations and instead said Sudanese soldiers encroached into its territory.
The latest skirmishes are a major escalation of tensions between the two eastern African countries which are also embroiled in a dispute over Ethiopia’s filling of a mega hydroelectric dam along the River Nile.