GENEVA, SWITZERLAND -- The United Nations said Tuesday that thousands of people were fleeing northern Ethiopia's conflict-torn Tigray region and the border area with Sudan now faced a full-blown refugee emergency.

"A full-scale humanitarian crisis is unfolding," UN refugee agency spokesman Babar Baloch told a virtual press briefing.

Some 4,000 people are fleeing across the border every day, Baloch said.

In all, more than 27,000 people have now streamed into Sudan since the conflict in Tigray erupted there two weeks ago.

"Refugees fleeing the fighting continue to arrive exhausted from the long trek to safety, with few belongings," Baloch said.

"The pace is very rapid," he said, stressing that the Sudan was now experiencing "an influx unseen over the last two decades in this part of the country."

Ethiopian Prime Minister Abiy Ahmed, last year's Nobel Peace Prize winner, announced a military campaign in the dissident northern region on November 4.

He said it came in response to attacks by local ruling party, the Tigray People's Liberation Front (TPLF), on federal military camps.

The TPLF dominated Ethiopian politics for three decades before Abiy came to power in 2018.

A bitter feud has grown as the party became sidelined, growing ever more defiant towards the central government.

Abiy has resisted calls by world leaders to cease hostilities and accept mediation.

The recent fighting has meanwhile left hundreds dead, although a communications blackout in Tigray has made it difficult to assess how the fighting is going.

It also remained unclear how many people had been displaced inside Ethiopia, but UN humanitarian agency spokesman Jens Laerke said given the number of people crossing the border "there may be massive displacement" inside Tigray.

Baloch also cautioned that the conflict was also "a major ongoing concern for the Eritrean refugee population" in Tigray, which he said numbered nearly 100,000.

"Potential for further displacement of refugees inside the country is increasingly a real possibility," he said, warning that the "humanitarian situation as result of this crisis is growing rapidly."