NAIROBI, July 13 (Reuters) - Forces in Ethiopia's Tigray pushed deeper into land claimed by neighbouring Amhara region on Tuesday, prompting its leaders - allies of the central government - to urge local militia to arm themselves and mobilise.
The Tigrayan advance and the Amhara response raised the possibility of the widening of a conflict that has aggravated ethnic and political divisions in Africa's second most populous country.
The push sparked calls from Amhara politicians for irregular militias to mobilise and arm themselves.
"Make quick preparations to mobilize to the fronts," said the statement from the National Movement of Amhara, a regional political party. The call was echoed by some local district governments in Amhara.
The fresh fighting follows a vow by the region's ruling party - the Tigray People's Liberation Front (TPLF) - to retake all territory within Tigray's borders it lost in conflict that broke out between the TPLF and Ethiopian federal forces in November.
The fertile fields of western and southern Tigray are also claimed by the Amhara region, which has been administering it since hostilities erupted in November.
The war pits Tigrayan forces - both formal and irregular - against the Ethiopian military and its allies from Amhara and the neighbouring nation of Eritrea. Thousands have died, more than 4 million people depend on emergency food aid, and nearly 2 million have been displaced since the conflict began.
Donors suspended some budget support to the government of Prime Minister Abiy Ahmed as reports of mass killings of civilians and gang rapes mounted, raising concerns over war crimes.
Spokespeople for the prime minister, Ethiopian military and government taskforce on Tigray did not respond to calls seeking comment.
On Tuesday, Tigrayan forces crossed the deep gorge of the Tekeze River and took control of the southern town of Mai Tsebri, an aid worker told Reuters. The aid worker, citing information received from colleagues there, said locals greeted Tigrayan forces with songs, cheers, and celebratory gunfire.
The fighting started overnight, two refugees living in a camp adjacent to the town told Reuters, saying gunfire began around 1 a.m. and continued intermittently for about 14 hours.
“We are on our own,” the first refugee said, asking for his name to be withheld to prevent reprisals. "We can’t run. Where would we go to?"
Getachew Reda, the spokesman for Tigray's ruling party, told Reuters that Tigrayan forces had also seized control of Alamata, the major town in the southern part of Tigray, on Monday night.
Both areas are claimed by Amhara, Ethiopia's second most populous region.
The push south follows three weeks of rapid territorial gains by the TPLF, which seized control of the regional capital Mekelle on June 28 after taking control of several nearby towns.
Abiy said the military pulled out of Mekelle to face threats elsewhere and the government declared a unilateral ceasefire, which the TPLF rejected.
Also on Tuesday, the U.N. rights council approved a resolution expressing deep concern about abuses in Tigray, calling for the swift withdrawal of Eritrean troops which it said were "exacerbating the conflict".
Dozens of civilians have told Reuters about rapes or killings by Eritrean troops. Eritrea's minister of information did not immediately respond to a request for comment but has previously denied any abuses. Eritrea spent months denying its troops were in Tigray at all.
"What is happening in the Tigray region in Ethiopia is appalling," said Ambassador Lotte Knudsen, head of the EU delegation to the United Nations in Geneva which brought the resolution.
Tigrayan leaders have said that Eritrean troops must withdraw before they will consider ceasefire talks.
Ethiopia's delegate, who is not currently one of the council's 47 members, categorically rejected the resolution.
"This resolution is a show of disdain for the ongoing joint inquiry with the intent of influencing its conclusion," said Ambassador Mahlet Hailu Guadey, referring to a probe by the state-run Ethiopian Human Rights Commission with the United Nations on alleged rights violations.
Ethiopia's Foreign Affairs Ministry also rejected the resolution as premature.
"There is no moral nor legal ground to justify the untimely adoption of a politically motivated resolution," it said in a statement.
Council member Eritrea also voted against the resolution.
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