NAIROBI - Ethiopia's allies are looting towns, arresting and killing civilians and relocating thousands of people from a disputed part of Tigray despite a truce between the government and local forces, witnesses and aid workers in the northern region say.

The violence raises fresh concerns about whether the ceasefire signed on Nov. 2 by Ethiopia's federal government and the Tigray People's Liberation Front (TPLF) - the party that dominates the restive province - will end two years of fighting that has killed tens of thousands and displaced millions.

Troops from Eritrea, to the north, and forces from the neighbouring Ethiopian region of Amhara, to the south, fought alongside Ethiopia's military in Tigray but were not party to the ceasefire.

However, the deal requires the withdrawal of foreign and non-Ethiopian National Defense Force (non-ENDF) troops from Tigray.

Eritrea fought a border war against Ethiopia in 1998-2000, when the TPLF dominated the central government, and remains the group's sworn enemy.

Eritrean troops have been seizing food, vehicles, gold, and even doors and windows from homes in at least a dozen towns in northern and northwestern Tigray since the ceasefire, according to four humanitarian workers and one resident, who like other people interviewed by Reuters asked not to be identified for fear of reprisals.

The troops also carried out extrajudicial killings and mass arrests in territory they control in northern Tigray, two residents and five aid workers said.

Eritrean Information Minister Yemane Gebremeskel did not directly address the accusations of looting and killings in a text message to Reuters but accused Tigrayan forces of "endless lies".

Ever since the start of the conflict in November 2020, human rights violations by all sides, including extra-judicial killings, raping and looting, have been documented by U.N. bodies, Ethiopia's state-appointed human rights commission, independent aid groups and media including Reuters. All sides have denied the allegations.

In western Tigray, Amhara fighters have conducted mass arrests and loaded thousands of ethnic Tigrayan civilians onto trucks before sending them east of the Tekeze River, according to two residents and two internal reports prepared by aid groups seen by Reuters.

Amhara leaders consider the river a borderline between Tigray and territory they say historically belonged to them to the west. Tigrayan officials say the area, which has fertile lands, has long been home to both ethnic groups and should remain in their region.

During the conflict, forces and militiamen from Amhara have been accused of moving Tigrayans elsewhere to change the ethnic make-up of the disputed area.

Gizachew Muluneh, spokesperson for the Amhara regional administration, did not respond to requests for comment. The administration has previously rejected claims that Tigrayans had been threatened or forced to leave their homes.

William Davison, senior analyst for Ethiopia at the International Crisis Group think tank, said the reports of abuses by Amhara and Eritrean forces could delay plans for the TPLF to disarm.

"Any serious failure in implementing the agreements raises the risks of a disastrous return to large-scale war," he added.

A spokesperson for the African Union, which is responsible for enforcing the ceasefire, did not respond to a request for comment. Neither did Ethiopia's national security advisor Redwan Hussien, military spokesperson Colonel Getnet Adane, government spokesperson Legesse Tulu, nor the TPLF's spokesperson Getachew Reda.

On Sunday, Reda tweeted that Eritrean forces had been destroying and looting property, as well as killing women and children.

"Will our partners for peace in Addis do their part of the deal to protect civilians and do whatever it takes to convince the 'external and non-ENDF forces' to leave Tigray?"

Neither Eritrea nor Amhara have said whether they will pull out of Tigray. They have in the past denied accusations of rights abuses in the region.

It is not yet clear how Ethiopia will deal with Eritrea and Amhara if their forces do not withdraw from Tigray, three diplomats close to the peace talks said.

The United States has said it will use sanctions to ensure the truce is respected and will hold to account those responsible for human rights violations.

FORCED REMOVALS

The Amhara regional government has welcomed the ceasefire but said nothing about the future of territory it seized in western Tigray, which Amhara officials previously said they would seek to annex formally.

A Nov. 16 report prepared by an aid group for six humanitarian agencies - including the World Food Program, the World Health Organization and the International Committee of the Red Cross - said that on Nov. 10 more than 2,800 men, women and children held for over a year in five detention centres in western Tigray were taken in trucks by an Amhara militia known as Fano.

They were released in a town called Adi Aser, before making their way on foot to Sheraro, outside the area that Amhara claims, according to the note, reviewed by Reuters.

Fano does not have a formal leadership structure so it was not possible for Reuters to seek comment.

An aid worker, who asked not to be identified, said thousands of displaced residents from western Tigray had arrived in the northern city of Shire in recent days, including women and children as young as three.

Most of the men had broken limbs, said the worker, adding that some of the men said they had been beaten while in detention by Amhara and Fano forces.

Reuters was not able to confirm independently his account.

(Reporting by the Nairobi newsroom, Writing by Tommy Reggiori Wilkes; Editing by Emelia Sithole-Matarise, Alexandra Zavis and Daniel Flynn)