Over the weekend, TPLF forces withdrew from Tigray’s main city of Mekelle, which is 115km (71 miles) south of Adigrat and is now under army control.
Eritrea was a key ally of landlocked Ethiopia during the 2020-2022 war, fighting against the TPLF in what was one of the most deadly conflicts this century and which drove the Tigray region to the precipice of famine.
But relations between the two neighbours have since deteriorated largely over the Ethiopian prime minister’s ambition to take ownership of one of Eritrea’s Red Sea ports.
Last week the two countries severed diplomatic relations as the renewed fighting raised fears of a wider regional conflict.
The BBC is unable to report from Tigray and surrounding areas, though mobile phone connections and internet access have been restored to most areas since the military took over Mekelle.
According to multiple accounts, Eritrean troops have moved from the border town of Zalambessa towards central Tigray, with convoys reportedly passing through Adigrat and heading toward Edaga Hamus, a town between Adigrat and Mekelle.
“I saw about 40 trucks carrying soldiers. The convoy was moving south,” one resident of Adigrat, who requested anonymity for security reasons, told BBC Tigrinya.