Nurah suspected her 13-year-old son was dead when the smuggler who claimed to be holding him hostage refused to put him on the phone. That was three years ago, but the series of events still runs through her mind every day.

Her youngest had left home, without warning and leaving no goodbye note or clue as to his destination. Nurah – originally from Eritrea – was already anxious because just a month earlier her older son had abandoned Sudan, hell-bent on making it to Libya and then across the Mediterranean Sea to Europe.

And then the angry man called, demanding a ransom of $2,000 for the younger boy. “I said if my son was alive I wanted to hear his voice, but they didn’t put him on,” she recalls, hunched over in a hot, cramped room in the Sudanese capital, Khartoum, her eyes staring firmly at the tiled floor.

Today, Nurah is on her own. Like most Eritreans and Ethiopians in Sudan she describes herself as a habesha – a second-class citizen. She used to work at one of the tea stalls dotted along the banks of the Nile river running through Khartoum, but unending harassment from locals and Sudanese security ended, she says, with two men following her home, kidnapping and raping her. Now she’s afraid to go outside.

Eritrean girls chat on a bed in the unaccompanied minors section of Shagarab refugee camp, eastern Sudan. Photograph: Sally Hayden

Nurah’s story (she requested anonymity because she fears retribution from smugglers or Sudanese security) is just one in a thick book of woes relating to Sudan. Here, young people are disappearing with startling frequency, many of them encouraged by smugglers to leave for Europe without telling their parents, who’ll be hit later with a staggering bill for the passage.

Conflict and poverty

Most Sudanese migrants, escaping conflict and poverty, want to go to Europe. It’s considered the closest safe region. But that’s gradually changing because of new restrictions on nongovernmental search-and-rescue missions off the coast of Libya, new money from the European Union to help Libya, Sudan and other African countries to stop migration, and new EU training for the Libyan Coast Guard, which is cracking down on Mediterranean boat traffic.

All this makes the trip to Europe more costly and difficult. But it has not stopped would-be migrants in Sudan – especially the young – from plotting journeys to what they expect will be better lives.

In Kassala, on Sudan’s eastern border, and in Sudan’s capital, Khartoum, smugglers are easy to find. In Khartoum, they’re often Eritreans who have made enough money to buy cars. Connections to smugglers are made through neighbourhood recommendations; a meet-up is likely after asking a few key people.

An Eritrean teenager sits on his bed in the unaccompanied minors section of Shagarab refugee camp, eastern Sudan. Photograph: Sally Hayden

“Smugglers are very organised, it’s organised crime,” says Ismail Omer Teirab, deputy chairman of Sudan’s National Committee to Combat Human Trafficking (NCCT). He believes what makes them difficult to root out is that gangs often work with the nation’s security forces. “First they bribe policemen. Otherwise they couldn’t get through the checkpoints.”

For those fleeing Eritrea – Nurah left because of forced unending military service and severe economic and social oppression – the journey from Kassala to Khartoum costs $300-$450 (€250-€380) for boys and men, and $750 for women. Why the difference? Families have been willing to pay more to ensure the safety of women.

Ransom fees

For those wanting to go further, passage to Libya costs from a further $1,600 and $1,800; going all the way to Europe from Khartoum – in a smuggler’s run – costs as much as $5,000, a fortune even for working refugees who earn as little as $50 a month as labourers.

When a ransom is added, the price skyrockets. And, if it goes wrong, some pay with their lives.

Children walk to school in Shagarab camp, eastern Sudan. Photograph: Sally Hayden

The one near-certainty facing migrants is that they will fall into steep debt to the money managers who facilitate the journeys. Those who brave the voyage often fall into the hands of militias operating a vicious slave trade inside Libya, where multiple governments and many tribes are locked in a struggle for supremacy.

Refugees and migrants who unsuccessfully attempted the journey to Libya say it is common for smugglers to sell them to other gangs once they draw near the Libyan border. Pretty soon, they no longer know who’s in charge, and the terms of their “contracts” can change without notice or negotiation. Some migrants are held in detention, suffering malnutrition and physical or sexual abuse. Others are forced to work until smugglers decide the debt is paid.

“Traffickers don’t keep their agreements. They’ll increase or double it and sell them to other traffickers,” said one 27-year-old Eritrean, whose friends recently set out on the journey and an unknown fate.

Europe “is only a hope, a wish”, he said.

The central Mediterranean Sea is currently the deadliest route to Europe. Some 600,000 people have crossed since 2014, while about 12,000 are feared to have died at sea. More than 2,800 are believed to have died so far in 2017.

Eritrean refugees play pool in Shagarab camp, eastern Sudan. Photograph: Sally Hayden

Police harassment

Migrants and refugees in Sudan commonly originate in Eritrea. In Sudan, their movements are limited. They claim they face harassment by the police, who regularly round them up, threatening deportation unless they pay bribes.

“The police every day arrest Eritreans and Ethiopians here. They ask for your ID card, make you pay $50. If you have an ID card they might take it and cut it [in half] says one Eritrean father.

“Some of the police live off refugees,” a Khartoum resident, who asks to remain anonymous, agrees. “They really get the brunt of it.”

Those who manage to get permission to work are often paid very little, and much less than a local would get.

The road to Europe is so difficult that many who today are trying to get across the Mediterranean are the second generation, sons and daughters of refugees who came to Sudan years ago. They see their parents being paid low wages, and suffering discrimination, police brutality and corruption, and decide they don’t want the same life.

An Eritrean teenager sits on his bed in the unaccompanied minors section of Shagarab refugee camp, eastern Sudan. Photograph: Sally Hayden

Meanwhile, smugglers search out young people and convince them to make the journey without telling their parents. “Go now, ask for money later,” they tell them. “That way no one can stop you.”

“I hid it from my family. I won’t tell my parents until I get to Libya,” explained a 24-year-old woman with delicate features in Khartoum. She says her parents have properties in Eritrea they can sell, a sacrifice that would leave them with nothing but if she is caught, she knows they will have to pay. “I will be exposed to slavery and sexual violence if they don’t pay.”

Danger and misery

Another 24 year old, a nurse from Eritrea who wants to be a doctor, says she is aware of the dangers: “I know but there is no more miserable life than this that I am now living. I want a chance . . . a better life.”

Two weeks ago, her 18-year-old sister tried to follow her to Khartoum, but was kidnapped on the Eritrean border. Her family have been told the ransom is $5,000, an impossible amount for them to pay. She worries that if the ransom is not paid, the girl may be moved up to the Sinai desert in Egypt. Among Eritreans, there are rumours that there is a trade in organ harvesting in that area, although the UN special rapporteur for Eritrea, Sheila B Keetharuth, says there is no evidence to prove those claims.

An Eritrean teenager sits on his bed in the unaccompanied minors section of Shagarab refugee camp, eastern Sudan. Photograph: Sally Hayden

“There are many who tried to go to Libya and they are dead,” says Azgiamin Tesialassi, a tired-looking Eritrean woman with braided hair, speaking in a dark, stone house in a low-income neighbourhood popular with refugees. “Some are lost in the desert and some at sea. For those who are dead, no one can help.”

As she speaks, she repeats the words “delalti haisebat” – which means human smugglers in her language, Tigrinya. “Our children are being kidnapped by smugglers here.”

“If trafficking is business, now how can we make it non-profitable? I haven’t an answer,” Ismail Omer Teirab, the National Committee to Combat Human Trafficking (NCCT) deputy chairman, says in an interview in Khartoum’s oldest hotel, the Acropole. At least 100 people each month make it into Libya, Teirab estimates, though exact statistics are impossible to collect in a vast area with little technology and record-keeping.

Education programmes

The NCCT was formed after Sudan adopted the much-lauded 2014 Human Trafficking Act. Teirab, a former teacher from Darfur, says he wants to run campaigns to educate refugees and Sudanese youth about the dangers of courting smugglers. He has received minimal funding – not enough for an office, other staff members, or even a photocopier.

“Every day young people see videos of Europe on their phones now, how can we combat that?” he asks.

Jeff Crisp, a research fellow at the public affairs think tank Chatham House and the former head of policy at the UN High Commissioner for Refugees, accepts that if the Mediterranean becomes an impassable barrier, it’s possible smugglers will begin sending people on new routes.

“It’s something a lot of people say: if one route closes it diverts into another,” Crisp says. “[But] it takes a while between one route closing off and then people taking up a different route.”

Among refugees in Sudan, there is little knowledge of the world outside the destinations already travelled to by family members or acquaintances from home. Most simply express the desire to keep moving until they find a safe space with opportunity. “I don’t know where would be good but I know I can’t stay here,” one refugee said.

Boys sit in their dormitory in the Shagarab refugee camp, eastern Sudan. Photograph: Sally Hayden

There is evidence that more migrants from northern and east Africa are even finding their way to South America, and by arduous and complicated routes. In one neighbourhood, families told of a Somali who ended up in Mexico, after he flew from Zambia to Brazil with a work visa. Another Somali travelled to Brazil from South Africa.

Another factor pushing migrants elsewhere is a growing recognition of the backlash against new settlers in Europe, and the magnitude of the Mediterranean crossing.

Talking tough

“Panic is the word I would use for the EU response to the whole refugee and migration issue over the last three years, it has really not got its act together and it has lurched from one thing to another,” Crisp says. “I think everyone thinks that there’s an importance in appearing and talking tough.”

Crisp says while it was obvious the EU was hoping people would no longer go on boats if rescues off the coast stopped, “that really depends on how much information [the migrants] have and what the smugglers and traffickers tell them”.

Tekulu, an Eritrean 24 year old in Khartoum, is due to make the journey north soon. He says smugglers don’t tell refugees the truth about the risks involved with these journeys, or give them adequate information about what the situation on the other side might be. “With the traffickers – no one tells you exactly how people live as refugees and how they arrive. They just tell you things are good.”

He is camped out in a sparse compound that has been used by countless Eritreans on their way through Sudan. The four other young men staying there on this particular day have been in Khartoum less than a month.

On Tekulu’s skinny bicep is a tattoo from the early days of his forced military training, the imprint carried out with a pen heated over a burning tire. “It was not more painful than what was happening around us,” he says.

Given what he’s been through, Tekulu isn’t willing to shatter illusions for those who will no doubt follow him. “Even if I tell them not to come, how can they stay here? It is good for me to keep quiet.”