Around 7,000 people have fled rapidly-escalating communal violence in western Ethiopia, seeking safety in neighbouring Sudan, the United Nations said Tuesday.
The region has long been plagued by competition over land and resources, and the UN said many people arriving in Sudan are seeking food, water and health care.
The displacement is not related to the unrest in Ethiopia's northern Tigray region, which has pushed more than 61,000 to flee also into Sudan in recent months.
Tensions have been high in the Metekel Zone of the western Benishangul-Gumuz region since 2019, with several reports of inter-communal attacks, the UN Refugee Agency, UNHCR, said.
A few hundred refugees crossed the border in November but the number has surged since then.
"The situation has rapidly escalated in the past three months," spokesman Babar Baloch told reporters in Geneva.
"The stories the refugees are bringing -- they are fleeing attacks from their opponents," said Baloch.
UNHCR said that of those who have reached southeastern Sudan's Blue Nile State, around 3,000 have so far been registered, while nearly 1,000 have been provided with humanitarian assistance.
"Refugees have received food, access to health, water and sanitation facilities, and aid supplies," said Baloch. The agency will "ramp up the response", he added.
Ethnic violence has been a persistent problem under Ethiopian Prime Minister Abiy Ahmed, who came to power in 2018 on the back of popular protests.
Contests over land and resources in Benishangul-Gumuz have spurred violence between ethnic groups.
Some leaders of the Amhara ethnic group, Ethiopia's second largest, have asserted ownership of Metekel -- claims that have inflamed tensions with ethnic Gumuz in the area.
Opposition politicians, notably Amhara, have in recent months been sounding the alarm about what they say is a targeted campaign by ethnic Gumuz militias against Amhara and Agew living in Metekel.
In late December, more than 100 civilians were killed in a massacre in Metekel.
The attackers set fields and homes ablaze, burning people alive as they slept, said the Ethiopian Human Rights Commission, a government-affiliated but independent body.
Ethiopia's military then killed 42 people allegedly among those responsible, regional authorities said.