Scorching heat, congested camps and a perilous journey await many fleeing Sudan's violence

The exhausted donkeys pulling carts overloaded with people and luggage across the border into South Sudan look as though they could buckle and collapse at any moment.

The same could be said of the fragile nation the new arrivals are fleeing to.

South Sudan,statistically the poorest country in the world, is being overwhelmed by an exodus of people fleeing the bloodshed in neighbouring Sudan.

A team from CBC News visited the remote border region between the two neighbours recently,an area which is extremely difficult for Western news organizations to access.

Before 2011,Sudan and South Sudan were part of the same country and still share some common demographics and culture.South Sudan has suffered from its own extreme violence in recent years, but after the first clashes in Sudan's capital ofKhartoum on April 15, people in the north began streaming across its open border.

Since then, aid agencies estimate more than 400,000 people have left,with roughly 80,000 arriving in South Sudan.

United Nations officials said last weekthey fear thatnumber could double or even triple in the months ahead if Sudan's army and the paramilitary group it's fighting don't make peace.

The violence in Khartoum has been especially vicious, with reportson Wednesday of 19 people killed and more than 100injured in an attack on a city market.

The Wunthou border crossing, near the South Sudanese town of Renk,is the most direct route south for people trying to get out of Khartoum, an eight-hour drive away.

In oppressive 40-degreeheat, families sat on rugs and suitcases, using donkey caravans to cross the final few hundred metres of no man's land.

"It's bad," said Hafiz Mohammed Ali, who spoke to CBC News just as he, his wife and four young children crossed the frontier. "Aircraft are [bombing] lots of places,so I just wanted to bring my family and be safe."

Another man,Issac Pham Vissel, also described aircraft bombing military buildings near his house, and said he and his family needed to get out.

"It's a very serious war," he said. "And I think it will be continuous."

A succession of ceasefires have come and gone with little effect.

The latest efforts to negotiate a truce ended Wednesday, when Sudan's army said it was breaking off talks with the Rapid Support Forces (RSF), the paramilitary group challenging it for control of the country.

The majority of those arriving in the Renk area are South Sudanese people who fled their own country's civil war between 2013 and 2016, and have once again been displaced by conflict.

Most have little to no support to rely on as they return to their former homeland.

At a pop-up health clinic that CBC News visited, Dr. Damres James says the constant displacements have taken a terrible toll.

"People are very distressed.They have post-traumatic depression. They always feel angry, because you don't have a place to stay and you don't have food to eat," she said.

Nor can Renk, and the destitute region surrounding it, handle such a rapid influx.

The townmostly made up of flimsy structures and thatched hutshas only very basic services.Necessities, such as gasoline, are hard to come by.

Various United Nations aid agencies have set up a transit centre and a temporary accommodation compound.There are tents andlatrines,and drinking water is trucked in.

But the camp is now bursting with more than 4,000 people. And the longer they stay,the more difficult it becomes to care for them.

Renk is 1,800 kilometres north of the capital,Juba, and the only road out is impassable. The solution has been to use convoys of boats to transport people up the White Nile River to the city of Malakal,which is more accessible and better served.

But it's an arduous journey.

The converted cargo haulers are little more than crude barges,with no seats or toilets for the two-day journey.

Between 300 to 400 people cram into whatever space they can find and cover themselves with blankets as a shield from the hot sun. One man pleaded with our CBC crew for an umbrella for protection, but there was none to give him.

At night,the boats pull onshore, where people can sleep and build fires to cook.

Among the aid workers trying to prevent the system from breaking down is Canadian Aaron Adkins, with the UN's International Organization for Migration.

He told CBC News the logistical challenges are overwhelming.

"We're at a point where we can't even get our own vehicles in here," he said. "We're scrambling to find whatever we can find that's working. And we're dealing with, yeah, broken trucks, broken buses all the time."

Adkins, 39, was born in Fredericton, N.B., and grew up splitting his time between Prince Edward Island and Kenya.

He says even when the arrivals reach Malakal, the problems don't end.

There have been disputes over food and water, and violence between different groups who've been jammed together in cramped conditions.

"Myself and the rest of the humanitarian community are very concerned about trying to get people to their intended destinations,"said Adkins.

"Because if we cannot, we will end up with a long-term humanitarian response that extends over years and years."

'Make or break' year

That view is shared by the UN's special representative for South Sudan,Nicholas Haysom,who's tasked with helping the country steer itself towardpolitical stability and democracy.

"The conflict in Sudan must be brought to an end,"he told CBC News at the United Nations compound in Juba.

"The longer it continues, the more South Sudan will experience the spillover effects of that war."

Even before the fighting broke out next door,the UN representative said South Sudan was facing what he described as a "make or break" year.

"It has to accomplish a set of preparations for free and fair elections. It has to draft a new constitution.It had two civil wars in a decade.It has to find a way in which people can live together harmoniously. And it's got to do that in the next 18 months," said Haysom.

Now add to all thata still-expanding humanitarian crisis.

More immediately,Western officials monitoring the humanitarian operation say they're concerned that moving all those new arrivals will very soon become much more difficult.

"Rainy season is coming," said Julius Egbeyemi,Canada's top diplomat in Juba,noting that trucks, and even the cargo boats on the White Nile, will have problems operatingin the heavy rain.

"Issues like health, personal accommodation, even disposal of waste becomes a problem. So this can easily be changed from a humanitarian to a health crisis."

Canada has had a continuous presence in South Sudan since its independence,with an embassy in Juba and almost $1 billion in development and humanitarian assistance.

Ottawa's latest announcement of money included $31 millionspecifically to help South Sudan cope with the fallout from Sudan's violence.

WATCH | CBC speaks with those crossing into South Sudan to escape violence:

On the front line of mass migration out of Sudan

1 year ago

Duration 7:36

Seven unrelenting weeks of fighting in Sudan have sent more than 350,000 people fleeing into neighbouring countries, including the worlds least-developed nation, South Sudan. CBCs Chris Brown travels to the border between the two countries, where a humanitarian effort is struggling to cope with the huge surge in migration.

As if South Sudan's situation wasn't precarious enough, its main economic lifeline a pipeline that takes crude oil through Sudan to the Red Sea is also under threat from the war.

Almost 98 per centof the entire budget for South Sudan's governmentis derived from oil revenues,and even a short interruption would be economically disastrous.

With borders on nine other African nations,almost all of whom are either in conflict or recovering from it,Haysom warnsSouth Sudan's ability to handle the spillover from Sudan has immense consequences.

"It would be foolish to ignore," he said."The consequences of an implosion in South Sudan will spread throughout the region."