Death is everywhere in Raqqa. Sometimes it lurks beneath the mountains of bomb-blasted rubble and pancaked buildings. Other times it peeks out from beneath the earth in the form of bones, hair and decomposing flesh the colour and texture of ancient dried parchment.

Often it moves around the city, its stench drifting on the humid breeze, creeping into the nostrils and psyche when you least expect it.

More than anyone else here, the men of Raqqa’s Civil Defence Unit know where death can be found. For going on six long months now they have sought out its many locations and collected its gruesome detritus along the way.

It’s early morning at the tumbledown fire station that acts as their base and already the men are kitted out in their dark overalls and red or yellow protective helmets. Around their necks most have already slung the thin cotton face masks that do little to ward off the dust and foul cloying odour that inhabits their 12 hour shifts in Raqqa’s ruins.

“We have a busy day ahead,” Dr Mahmood Ibraheem tells me, as the rest of the crew loiter around smoking a final cigarette or finishing their glasses of heavily sweetened tea. A small portly man with an unkempt beard, Ibraheem is wearing a bright yellow baseball cap with the word “Desperados” emblazoned in scarlet across the front.

His unusual head gear seems right for a man clearly larger than life. Today just like every day, he will examine the corpses and body parts the team uncover, checking if the victims are male, female, old, young, civilian or jihadist fighters from the ranks of the Islamic State (IS) - or Daesh as the terror group are commonly referred to here using the Arabic acronym.

Doctors, let alone forensic pathologists, are almost non-existent in Raqqa these days and Ibraheem, a GP, has found himself thrust into an unfamiliar and unforgiving role.

“There is a serious shortage of all kinds of doctors and medical specialists,” he tells me as we prepare to leave the fire station. “I have to do this job now, there’s no one else and we must at least record some of the details of those remains we find even if we can’t identify the victims,” Ibraheem insists. “It is a human rights necessity as well as a medical one,” he adds after a pause.

A short time later when I accompany him and the team in some backstreets and alleyways flanked by canyons of ruins, I begin to realise the scale and hazards he and the forty or so other members of the Civil Defence Unit face.

All around us stand what were once inhabited multi-storey apartment blocks that have been prised apart by the terrifying force of powerful explosions.

Everywhere the buildings’ pillars, pipes, electrical cables and twisted iron work have been spewed out like the innards of some disemboweled animal. It’s estimated that more than 11,000 buildings in Raqqa were destroyed or severely damaged between February and October 2017 during US-led airstrikes.

Today the city is all but unrecognisable even to those who know it well and have returned from across Syria to try and rebuild their lives.

For many, gone are their houses, while the hospitals, bridges, schools and factories they once used or worked in have been laid waste. For those brave and determined enough to return, there is virtually no electricity and little clean water. Only a few days ago as I journeyed across the city a heavy downpour left many streets flooded with up to six inches of filthy water in which floated the uncollected refuse that lies in heaps everywhere.

Before the death and destruction that came to stalk Raqqa the city was home to about 400,000 people, many living in high-rise apartments. Today the intimate reminders of those who lived in the district in which the team worked that day still lie scattered by the maelstrom that engulfed their lives.

In the storeys above us torn carpets and curtains hang like shrouds while on the floors just visible lie schoolbooks, coat-hangers and sandals, a child’s cot, toys and other personal belongings.

Virtually no building, no wall, no surface, has escaped the destructive firepower unleashed over the five months this Syrian city was subjected to siege and ferocious battles as Kurdish-led Syrian Democratic Forces (SDF), backed by US air and artillery strikes struggled to oust IS from Raqqa, the self-proclaimed capital of their Islamic caliphate.

According to independent research groups that track American and Russian airstrikes in Syria, US aircraft and artillery bombarded Raqqa with an estimated 20,000 munitions during the five month operation. This is more than was dropped in all of Afghanistan in the whole of 2017.

“We have already found about 70 corpses in this one spot,” Ibraheem shouts in my ear over the clamour of earthmoving equipment shovelling rubble into mounds which the firemen then scour by hand wearing only thin surgical gloves in search of body parts or corpses. The resources the team have are shockingly basic and meagre. Such are the shortages they face that even the body bags used for their grisly collection are recycled after emptying.

Despite this the men work methodically. At times they appear to float as ghostly apparitions in the fog of white dust that hangs in the air clinging to their overalls and filling their noses and lungs.

Constantly there is the danger of the buildings above crumbling on top of them. Then there is that other threat too of disrupting the countless unexploded ordnance and Improvised Explosive Devices (IED’s) or booby traps left behind by desperate IS fighters during their last stand in the city.

Those few records that have been kept recently by organisations like the Kurdish Red Crescent and Doctors Without Borders in Raqqa since IS was forced out of the city, show that over 1,000 adults and children have been injured or killed by IED’s and other ordnance since October, but the true number is likely much higher. For the civil defence teams these terrors in the rubble are their greatest threat and fear.

Less than a mile from the devastated apartment blocks where the first team is working, that threat is equally daunting for a small group of firemen busy uncovering a mass grave in one of Raqqa’s city centre parks.

Surrounding the entire square the buildings are little more than skeletal shells, and by the roadside the burnt out carapaces of vehicles, many upturned as if tossed by some giant hand, are also testimony to the destructive firepower unleashed here.

When I arrive three blue body bags already filled sit by the ditch in which the firemen are labouring with shovels and pick axes in the oven-like midday heat. Clouds of flies hover over the ditch and body bags. The smell is stomach churning.

“Such a waste of human life and the terrible destruction of the place in which we once lived, it makes me so angry,” says Mahmoud Jassm, the 30-year-old leader of the team who like many of the men is also a volunteer with the unit. It’s all a far cry from Jassm’s previous role as a PhD student studying Arabic language and literature before war came to Raqqa.

“Men, women, children, mostly civilians but we find many Daesh fighters too both in the graves and the rubble,” Jassm says, bending forward to peer inside at one of the victims in the body bags that is wrapped in a heavy blanket.

“Look, it’s a young women, she can’t be more than twenty-five years old,” Jassm says, the sense of frustration evident in his voice.

“Sometimes at the end of a day, I feel no good,” he confesses shaking his head, giving the impression of a man on the edge of despair. The physical and psychological stress that he and his colleagues face is unimaginable.

Firemen here who routinely handle dead bodies risk contracting tuberculosis and gastrointestinal infections, as well as suffering potential effects of trauma on their mental health.

Despite this Jassm regards what he and his team do as “rescue work,” saving the victims from anonymous oblivion, but the reality right now is that very few of the bodies recovered can be identified. With no existing capacity to do DNA testing, many of those found are inevitably simply moved from where they are found to another mass grave created by the authorities on the outskirts of the city.

Of those that can be identified it’s usually from locations where surviving family members have known them to have died and been able to positively identify loved ones from personal items found alongside them or from clothing.

At the height of the siege in the city many bodies were disposed of hurriedly by IS fighters who often dumped civilian dead and the corpses of their own men into unmarked mass graves.

In the heart of the city’s central district where I accompanied the civil defence teams, scores of bodies had already been recovered from a mass grave under a football pitch, close to a hospital where the jihadists had dug in before being routed from the city.

“It could contain hundreds of bodies, we haven’t finished working there yet,” Yaser Khamis the head of the Civil Defence Unit told me, as I prepared to follow yet another of his teams to an apartment block where a handful of civilians returning to their homes had reported an overpowering stench suggesting corpses were close by.

It was a tight narrow stairwell that led to the first floor where one of the families lived, some of whose members were waiting for the arrival of the team.

“Upstairs,” said an elderly man pointing to where the smell came from, his granddaughter standing alongside him holding a cloth over her nose and mouth and clearly terrified.

Moving cautiously, the team almost instantly came across the remains of the first body in a room, one wall of which had been blow out by an explosion. I watched as one fireman tentatively probed at the bones, hair and decomposed heap on the floor with a stick before he and his colleague suddenly stepped back.

"Daesh,” he said, the tone of his one word warning suggesting that he had encountered something dangerous. Moving tentatively he stepped forward to tie some rope to what he warned was the remains of a suicide bomb belt before retiring behind a nearby wall for cover and slowly pulling on the line to remove the belt which on this occasion proved immobilised.

On the roof top outside meanwhile, the remains of another IS fighter was also discovered.

“This one, used his belt, killed himself,” one fireman told me in broken English, as the body parts of both jihadists, bigger bones and hair still visible were loaded into a body bag by the team.

Downstairs in the neighbourhood’s Rabiah al-Puqqii Street, bystanders looked on in horror covering their mouths and noses with sweaters and shirts against the smell as the remains of the two fighters were loaded into an ambulance. Minutes later they were transferred into a nearby pick up truck bringing the day’s gory tally of body bags to a dozen so far.

On average the team will unearth anything between 15-25 bodies or remains every day. Since the end of the siege the Civil Defence Unit has recovered more than 300 corpses the vast majority of which they believe to be civilians. Right now though there are 6,000 open reports of human remains in the rubble of Raqqa and many believe this to be a fraction of the total.

As the team’s long exhausting shift drew to an end there was one more duty to perform that day. Accompanying the pick up truck I followed a few members of the team to a makeshift cemetery on the outskirts of Raqqa. Here in an area the size of a football field, the remains of the dead that have been recovered from the cities ruins are interred.

Long trenches hewn out by bulldozers lie in parallel lines. Before burial the remaining few members of the team gather in a group to say prayers over the blue body bags that lie before them on the ground. As they shift the bags into position one accidentally opens momentarily and I catch a glimpse of what remains of an infant still dressed in a striped top, wisps of hair on the boy or girl’s head moving gently in the breeze.

“It makes no difference to us if they are Daesh or civilians, they are all human beings and deserve to be seen as such by us and by God,” one of the team tells me after the prayer and they begin to place the remains gently into the mass grave. Once again civilian victims and Daesh fighters lie together. This time though it will most likely will be their final resting place.