At the Hamdayet river crossing between Ethiopia and Sudan, men, women and children packed into rickety boats are braving the strong currents every few minutes.
On the Sudanese side of the Tekeze river, a mother-of-six stands in a bright pink headscarf with a small umbrella to keep the sun off the baby boy strapped to her back.
As she tries to explain what happened to her in broken English, she breaks down in tears.
“My house is destroyed. I do not know where my husband and son are. They are still there,” Ms Tsegay said, gesturing across the river. “Please, we need help.”
Two weeks ago, Ms Tsegay fled heavy fighting in the town of Humera, which lies about 20km west of the river, with five of her small children.
Instead of moving on to one of the refugee camps in Sudan, she has waited for 10 days near the Tekeze river to see if she can spot her loved ones on one of the boats.
“[The authorities] want us to leave here and go further into Sudan,” she said. “But how can I leave without my family?”
The ensuing fighting and communications blackout has torn thousands of families apart. Many refugees in Sudan told The Telegraph they had not spoken to loved ones for three weeks and did not know if they were dead or alive.
According to the United Nations, some 40,000 people have already fled the conflict into the arid wasteland of Eastern Sudan. Sudanese NGOs and international humanitarian organisations are scrambling to build enough camps to house them in Sudan.
Many say they have walked for days, carrying little more than their identity papers.
Now there are mounting concerns that Ethiopia is trying to prevent any more people from crossing the border in order to quieten the growing international condemnation.
Sky News reported on Tuesday that government forces were holding back a large number of refugees and preventing them from fleeing into Sudan, according to military sources.
The reporting backs up multiple refugee accounts The Telegraph has heard over the last few days. One mother-of-five who made it to Um-Rakoba refugee camp several days ago said that soldiers had threatened to cut her head off if she tried to escape.
Back on the riverside in Hamdayet, hundreds of refugees take their time to wash in the cool water. Some new arrivals embrace friends in a moment of happiness; others lie exhausted in the shade.
After a while, some begin to slowly walk up the dusty hill towards the registration centre about 1 kilometre away, where two dozen British-made Bedford buses stand in a line with their engines grinding away in the midday sun.
Every day, humanitarians and the Sudanese government are using the battered buses to transport hundreds of refugees to camps.
In the midst of the fumes and billowing dust, Hagos, not his real name, looks tired and defeated.
A tall man in a blue T-shirt with a small moustache, he is still searching for his family.
“I am checking every bus for my wife and daughter. But I cannot see them,” he said. “I can’t call them because the phones don’t work in Tigray. I don’t know where they are.”
Three weeks ago, Abiy Ahmed, the Nobel Peace Prize-winning Ethiopian prime minister, launched a military campaign in the country’s northern Tigray province against the regional government, the Tigray People’s Liberation Front (TPLF).
The federal government in Addis Ababa cut power, internet, phone lines and banking services to the mountainous region and barred humanitarians and most international journalists from travelling to the region, making it difficult to know exactly what is going on.
Ethiopia’s federal government says its forces are doing their utmost to protect civilians and accuse forces loyal to the TPLF of killing people en masse.
But dozens of refugees from Western Tigray who The Telegraph has interviewed in recent days claim they have been bombed indiscriminately and attacked by federal soldiers and knife-wielding allied militiamen.
Mr Abiy has resisted calls for mediation and on Wednesday morning warned the international community not to “interfere”, insisting his government was "very much capable" of resolving the matter on its own.
"While we consider the concerns and advice of our friends, we reject any interference in our internal affairs," Mr Abiy said.
"We therefore respectfully urge the international community to refrain from any unwelcome and unlawful acts of interference and respect the fundamental principles of non-intervention under international law."
The statement was made just hours before a 72-hour deadline was due to elapse later Wednesday for Tigray's leaders to surrender or face an assault on their capital, Mekele.
Ethiopian forces say they are encircling the city of half a million with tanks and have urged all residents to leave.
Rights groups have warned that attacking the city could constitute a war crime. As the clock ticked down, the UN Security Council held its first meeting on the three-week-old crisis.
Fighting between the Ethiopian army and Tigrayan forces has raged since November 4, when Mr Abiy ordered a military response to what he said were TPLF attacks on federal military camps.