Oct 13 (Reuters) - Ethiopian government troops have advanced to a town on the border with Eritrea previously controlled by Tigrayan rebels, people in touch with residents said on Tuesday, as diplomats scrambled to avert war between the Horn of Africa neighbours.
Witnesses and a conflict monitor said Eritrean troops had crossed last week into Zalambessa, near Ethiopia's northernmost point, in support of the rebels, but it was unclear if the Eritrean troops or rebels were still present on Tuesday.
Asmara has denied any incursion into Ethiopia and asked the UN to take deterrent measures against Ethiopia. It argues that Addis Ababa's accusations of an invasion by Eritrean forces amounted to a "declaration of war".
Fighting broke out in Ethiopia last month as a rebel alliance led by the Tigray People's Liberation Front (TPLF) went on the offensive, reigniting a war that killed hundreds of thousands between 2020-22.
With Addis Ababa and Asmara now on opposing sides again, conflicts raging elsewhere in the region and tensions high across the Red Sea, there are fears of broader contagion of violence this time around.
The Ethiopian government's counter-offensive has driven rebels from a string of towns, forcing them to retreat north.
By Tuesday, the army had reached Zalambessa, a town with a population of around 15,000 on the Ethiopian side of the border with Eritrea, according to six sources. The sources included four people in touch with residents, a diplomat and an expert on the conflict in touch with the warring parties.
A spokesperson for a pro-government militia did not confirm the military taking control of the town.
Spokespeople for Ethiopia's military and Ethiopian Prime Minister Abiy Ahmed did not immediately respond to requests for comment.
DUELLING UN LETTERS
Having been locked in conflict for years, Ethiopia and Eritrea made peace in 2018 and Eritrea fought in support of Ethiopia’s federal government during a 2020-2022 civil war in Tigray, but relations have since soured again.
Ethiopia has accused Eritrea of backing the rebels and wrote to Security Council members, stating that Eritrean troops had advanced up to 60 km (37 miles) inside Ethiopia.
Eritrea's Foreign Minister Osman Saleh has asked the Security Council to take action against Addis Ababa in a letter seen by Reuters, invoking Chapter VII of the UN Charter, which allows for measures ranging from sanctions to military action.
On Tuesday, Security Council members were due to hold a closed-door meeting on the situation in the Horn of Africa, the Greek presidency of the Security Council said.
The issue of sea access has also roiled relations.
Ethiopia had access to a coastline for decades until Eritrea gained independence from Addis Ababa in 1993. Ethiopia argues that restoring sea access is an existential issue but has said it would be restored through peace and dialogue.
(Reporting by Nairobi newsroom; writing by Ammu Kannampilly; Editing by David Lewis)
