Belgrade, Serbia - Patches of ice dot a grassless yard where a group of refugees and migrants heat a barrel of water on a campfire to bathe and handwash their clothes on a dimming afternoon in early January.

A teenager from Pakistan sits on his haunches and shivers as he waits for his friend to pour a bowl of hot water down his back, wearing only a pair of undershorts.

Young men sit in tight rings around the campfires. Smoke cylinders rise from the centre of each circle, the wind picking up, dragging the dark grey plumes against the air.

The other side of the street is lined with hotels, cafes and restaurants. Within eyeshot is a construction site for Belgrade Waterfront, a controversial real estate project that will place a high-rise tower and luxury apartments along the Danube River.

Fawad Wakili, an 18-year-old who fled Afghanistan's Kabul four months ago, is among the estimated 700 refugees and migrants sleeping in and around the abandoned buildings behind Belgrade's central bus station.

As of November, the United Nations estimated that more than 6,000 refugees and migrants were in Serbia.

IN PICTURES: Afghan refugees stranded in Serbia

Fawad, a thin youngster who looks younger than his age, says he left after receiving threats from Taliban members. He has been here for more than two months, sleeping huddled up next to others in a corner in one of the several abandoned buildings on the plot of land. Rolled up in dirty blankets, they keep warm by burning scrap wood and rubbish in bins inside the buildings.

Along with many of his fellow campers, Fawad is struggling to overcome a cold and a chest-rattling cough he developed amid a combination of wintry weather and excessive smoke inhalation. "It's the third day I'm sick," he says. "The problem is the weather is very cold and inside the buildings there are [camp]fires everywhere."

Each morning, Fawad wakes up and walks to a nearby park to ask for dry blankets from the UNHCR, the United Nations refugee agency. With no money, he has been able only to procure a few Ibuprofen tablets for his cold, which worsens each day.

Hoping to reach France and continue his education, he has been sent back from the Croatian border three times since he made it to Serbia. He says Croatian border guards beat him and others who tried to cross the border before pushing them back into Serbian territory.

Scared of returning to Bulgaria

Unable to continue the journey westward owing to the closed borders, Fawad fears registering in an official Serbian camp and risking deportation back to Bulgaria, where he was registered in accordance with European Union migration rules.

An estimated 361,019 refugees and migrants fled war and economic devastation to reach European shores by boat last year, while more than 5,000 died or are still missing at sea, according to the UNHCR. In 2015, more than a million made the often-fatal journey across the Mediterranean Sea.

Others have reached Europe by land, crossing from Turkey into Bulgaria and moving on through the Western Balkans. In March 2016, the Balkan route was effectively sealed after several countries closed their borders to refugees and migrants.

As part of the Dublin Regulation protocol, refugees and migrants can be deported to the country they were first registered in upon entering the EU. For Fawad, the prospect of returning to Bulgaria ignites fears of de facto imprisonment, as well as being beaten and robbed by authorities and vigilantes.

In addition to extortion and robbery, rights organisations have decried Bulgarian authorities and civilian-led militias for violence and ill treatment of refugees and migrants.

READ MORE: Refugees in Bulgaria endure 'robbery, extortion and theft'

In December 2015, the Belgrade Centre for Human Rights and Oxfam published a joint report accusing Bulgaria of "extortion, robbery, physical violence, threats of deportation and police dog attacks".

A month later, Human Rights Watch said Bulgaria had subjected refugees and migrants to "unlawful treatment", including summary deportations to Turkey.

While attempting to catch a bus from Sofia to the Serbian border several months ago, Fawad and several others were arrested by Bulgarian police and sent to a closed camp, where they were fenced-in and effectively jailed.

"In one room, more than 50 people were there," he says, recalling being punched and pushed often by camp guards. "Bulgarian police … are really bad people. They are not like humans [with us]."

He later left the camp and made it across the Serbian border.

In late November, Bulgarian Prime Minister Boiko Borisov said more than 1,000 Afghan refugees would be moved and hundreds expelled after clashes with guards in a closed refugee centre. Hundreds were subsequently transferred to other facilities.

The Bulgarian prime minister accused protesters of "acts of vandalism" and vowed that they would be "brought to justice".

More than 17,000 refugees and migrants were detained in the first ten months of 2016.

'Are you hungry?'

Imran Khan, a 26-year-old who was a soldier in the Afghan security forces, left behind his wife and child in Kabul with the hopes of reaching Europe. He says Taliban fighters threatened him in the months before his departure.

The thin man has a small patch of hair on his chin and rubs his gloveless hands together as if he is attempting to start a small fire between them. The wind picks up. He shivers and rocks back and forth while recalling his departure from Afghanistan and the months-long journey through Iran, Turkey and Bulgaria that landed him in Serbia.

"I am from Kabul, but I was with the army in Helmand province," he says. "When you are in the army or involved in government activities, you will have threats from the Taliban."

Asked where he hopes to apply for asylum in the EU, Imran says simply: "Anywhere."

READ MORE: 'Afghan refugees are not fleeing by choice'

A group of young men stop and listen as Imran speaks, nodding in agreement. "You see the conditions here," says one man who didn't provide his name. "I haven't seen anything like this in my dreams."

Another young man, who also didn't offer his name, saunters across the parking lot, weaving around slick, frozen patches as he approaches a brick building with glassless cadavers where the windows ought to be.

He is carrying a small pot of potato soup back to his camp area to share with friends. He stops for a moment. "Are you hungry?" he asks, lifting the fire-blackened pot as an offer.

Explaining that he left Pakistan with the dream of finding a new life in Europe, the young man says he is holding out for the borders to open again. He then says bye and disappears into a mass of black smog inside the building.

During the pre-dawn hours of the following morning, several centimetres of snow fall in Belgrade and the surrounding areas, leaving the refugees and migrants living behind the bus station even more exposed to the elements.

Sinking temperatures

With temperatures expected to drop to a low of 13 degrees below zero over the coming weekend, the difficulties faced by the impromptu camp's residents will multiply.

Neither the Office of Serbian Prime Minister Aleksandar Vucic nor the government's Office for Media Relations replied to Al Jazeera's inquiries about the government's preparations to ensure the safety of refugees and migrants amid the plummeting temperatures.

Noting that more than 651,000 refugees and migrants had entered Serbia in 2015, Vucic said in March: "If no common European solution is found [for the refugee crisis], we will behave humanely and respect the principles of solidarity."

Yet in November, the Serbian Ministry of Labour and Employment issued a statement announcing a ban on NGOs from providing refugees and migrants who live outside of government-recognised camps with food, blankets and clothing.

The legal consequences of the ban, which doesn't prohibit providing medicine, are unclear, and the Hot Food Idomeni organisation has nonetheless continued to bring food once a day.

READ MORE: 2016 - The year the world stopped caring about refugees

Lydia Gall, a Balkans researcher for Human Rights Watch, describes the ban's intentions as "very problematic", alluding to a shortage of basic supplies in government-administered facilities. "Even if you live in a camp, you're not being provided very basic items, such as a jacket," she says.

In some cases, Gall explains, many refugees and migrants - particularly young males - have tried unsuccessfully to register for a spot in refugee camps. Others avoid going to the camps for fear of being swept up by authorities and expelled from the country.

"You stand the risk of being sort of ambushed in the middle of night by Serbian police and sent back to Macedonia or Bulgaria," Gall adds.

Back in the impromptu camp, a food line stretches across the yard. As the sun gradually retreats, a group of teenagers kick a football back and forth, occasionally punting it at a concrete wall. Others play cricket with an old tennis ball.

Fawad says he has been unable to reach his parents since he first left Kabul four months ago. "I'm worried about them," he explains, a look of uncertainty forming on his face. "And I don't know [what to do], but I don't want to go back to Bulgaria."

He points in the direction of a man who squats and cups in his hand water from one of the heated barrels. In quick, jerky motions, the man splashes the water on his face and bare chest. Steam rises off his back as he trembles in the piercing wind.

Fawad shakes his head slightly in a manner that suggests both disbelief and hopelessness. "In two hours, he will be sick."

Follow Patrick Strickland on Twitter: @P_Strickland_