AS he speaks a trickle of sweat runs down my back. It’s as if suddenly the grisly story he is telling has made the stifling heat feel even more oppressive.

“They cut off people’s heads with knives and placed the heads back on top of the shoulders,” Abbas tells me.

“The decapitated bodies were left to rot in the street without burial, a sign that Boko Haram regard them as Kafirs – non-believers – and as a warning to others,” he continues.

Inside the crumbling ochre-coloured concrete hut in which we are standing, it is now almost unbearably hot. The midday sun beating down on the corrugated tin roof has turned the interior into an oven.

It’s the final months of north-eastern Nigeria’s dry season and from dawn until dusk the heat intensifies. It consumes, envelops everything, bouncing off the few tarmac roads and broiling the dust on dirt tracks here in Gombe State.

Nigerians call Gombe the ‘jewel in the savannah’. But nothing much glitters here.

Gombe might not be much of a jewel, but for people like Abbas and his family it is a precious sanctuary of sorts.

For days now I have listened to stories like his. The stories of those who have sought refuge here. Most are disquieting accounts, the experiences difficult to comprehend and near impossible to imagine anyone living through.

Survivors like Abbas and his family are the lucky ones. Many others never manage to escape the brutal rule of Boko Haram, one of the world’s most murderous terror groups that calls itself the West African wing of its equally barbaric big brother, the Islamic State (IS).

Even before speaking with Abbas I sense from the faces of his family some of the trauma they had undergone during the five months that Boko Haram had stalked their village, Nduva, in neighbouring Borno State.

“We had to stay indoors much of the time and couldn’t go to our farms, there was little food and water and always Boko Haram slaughtering people,” Abbas tells me.

Nearby clearly exhausted, his elderly mother, wife and children sit in the dust of the sparse rundown compound in which they now shelter.

Lined up along one wall are a handful of bulging trolley bags and holdalls containing all the personal belongings they could carry during the five gruelling days it took them to escape their village and come here to Pantami an impoverished neighbourhood in Gombe.

Abbas well remembers the day Boko Haram came to his village, their black flags fluttering from the speeding pick-up trucks that had heavy machine guns on tripods bolted down in the back. Some fighters also arrived on motorcycles and others on foot, quickly overrunning Nduva.

“The moment you violated their instructions they either cut your throat or shot you,” he recalls. “I saw people tied up crouching, waiting to be butchered in this way.”

For what seemed like endless months, Abbas, his family, neighbours and other villagers lived in constant fear, struggling to survive as the cost of basic items soared.

It was only when the Nigerian Army fought its way into the area and gaps in the Boko Haram defences opened up that Abbas family and a handful of others managed to slip away. In the days that followed, they trekked over 60 miles across scrubland studded with acacias and baobab trees that provided the only shelter from the searing sun. Finally they arrived at the town of Damboa, from where they journeyed to the comparative safety of Gombe.

Nigeria is the world’s 10th largest oil producer, but just as quickly as it pumps out its 2.4 million barrels of oil a day, so Boko Haram’s scorched earth tactics spew out a gigantic flotsam of displaced humanity that now stands at 2.2 million people.

As major world humanitarian crises go, this ranks with Syria, South Sudan and Yemen, but rarely makes the world headlines.

Some 17,000 people are said to have have died as Boko Haram captured large swathes of territory in three north-eastern Nigerian states. With access to many areas off limits this is a conservative estimate, and most human rights and humanitarian groups warn that the true figure is most likely far greater.

Along the way the jihadists have consistently been forcing young men into their ranks and kidnapping and raping young women and girls.

This month marks the second year since the abduction of 276 schoolgirls by Boko Haram from a secondary school in Chibok.

It was on April 14, 2014 when the girls were asleep in their dormitory that several dozen armed Boko Haram fighters overran the premises, herded the girls onto trucks, set fire to the school and drove their hostages into the bush.

The attack was very much in keeping with the group’s aims. Loosely translated from the region’s Hausa language, Boko Haram means, “Western education is forbidden.”

Ever so briefly, the mass abduction for once made the headlines and the world united in outrage as the global social media community rallied round a call to #bringbackourgirls.

But that was two years ago and since then little has been heard of the schoolgirls and the kidnappings continue with many more young women forced into sexual slavery.

Boko Haram has respected the age or gender for those living under its shadow. Forty-year-old Jummai knows this all too well. She herself comes from the same Chibok district in Borno State where barely six months after the schoolgirls were abducted, the wrath of Boko Haram was inflicted on her own community.

“It started at 11am and I was at a little mini restaurant in town,” Jummai recalls of that day.

In the chaos that ensued Jummai managed to slip back briefly to her house but there was no sign of her children and husband so she fled into the bush.

It was during that time in the bush that she came across a family of five other children who had become separated from their parents and were now hiding.

“Not being able to find my own kids, I could only imagine what the mother of these children was thinking, so took them under my care,” she says.

For the next three days with no food or water Jummai and the children, having managed to escape with only what they were wearing, dodged Boko Haram fighters combing the district.

Today Jummai and her husband, who were reunited in Gombe with their own four children, still care for the five children she found in the bush, the youngest of whom, Joel, is 12 and the eldest, Hanna, now 17.

Sitting in the shade of a baobab tree in the heart of Gombe town I ask Joel how life is for him now?

“Things are good, but not so good, I still dream about my parents,” Joel tells me, before the other children chip in saying that at night before sleeping they often all sit together and reminisce about their parents.

Despite the horrors they have experienced, they tell me that in Gombe some local youngsters pick on them because they are outsiders and come from areas where the terrorists operate.

“They call us Boko Haram, but if they had seen what we have seen they would not say such things,” one of the girls says quietly.

In the two years since they fled Chibok, the children have not met anyone from their family, relatives or neighbours and the fate of their parents is still unknown to them.

In the meantime only the incredible kindness and selflessness of their carer Jummai, has prevented them from an unknown but most likely terrible fate.

As is so often the case in regions wracked by conflict and poverty it is women, children and the elderly that bear a disproportionate burden of hardship.

Humanitarian agency Mercy Corps has been working in the host communities of Gombe since 2014.

In that time its aid workers here have seen the needs of the displaced rise dramatically despite reports that Boko Haram is militarily meant to be on the back foot and losing ground to the Nigerian Army.

“Yes they have been weakened, but their capacity to attack vulnerable villages is on the increase and they they are now striking soft targets like markets where people gather,” says Michael Muazu, Humanitarian Projects Manager for Mercy Corps in Nigeria.

So bad is the situation in the region now, that the agency, whose European headquarters are based in Edinburgh, has made the crisis one of its three top global humanitarian priorities.

Muazu says that because of a lack of access to areas affected no-one fully knows the magnitude of those affected by the Boko Haram insurgency, but that “the needs are huge.”

“Whole areas have been raised and a lot of people displaced that now lack basic services, like potable water, access to health care, schooling for children or money to buy basics,” he says.

Mercy Corps works not only with the displaced but those in the host communities who were already vulnerable before the arrival of those uprooted by Boko Haram.

For many people beyond Nigeria’s shores this most populous country in Africa is perceived as an oil-rich state from which the majority benefit. But nothing could be further from the truth with most of the country’s citizens surviving on the equivalent of $1 dollar or less a day. This perfect storm of poverty and displacement leaves north-eastern Nigeria in desperate need of humanitarian support.

Michael Muazu confirms that it is women, children and the elderly that are often most at threat: “Most of the male heads of the households are not around having moved to look for work elsewhere, so women and children are those left behind and are vulnerable,” he says speaking in Mercy Corps’ office in Gombe.

A few hours later not that far from where we spoke I was to see evidence of this for myself. In the dusty backstreets of Pantami neighbourhood in Gombe, I asked Naomi a widowed mother of four children how she managed to make ends meet.

“Mercy Corps has given me money for hygiene items and food assistance, helped me with my children now they give me livelihood support,” she tells me, surrounded by some of the food stuffs she now sells as a petty trader on the streets of Gombe. “Right now I cannot go back home, my husband is dead my house burned to the ground so my life is here now,” Naomi continues, her two-year-old son Amos lying sprawled out on the floor of their tiny hut, sleeping and suffering from a fever.

It’s a far cry from the happy life she had previously when her husband was a farmer and car mechanic until the night Boko Haram gunmen burst into their home as they all slept.

“They saw my husband lying down and they shot him on the neck and when they saw he was still breathing they shot him in the head,” she remembers of that dreadful night, the memory clearly still a very painful one to revisit.

Having killed Naomi’s husband, Boko Haram did not finish there, going through the house room-by-room to where her husband’s three younger brothers were spending the night. They too were riddled with bullets without hesitation.

Hoping to find safety Naomi rushed to her mother-in-law’s house only to find Boko Haram burning homes there too.

Having fled to Gombe, Naomi and mother-in-law Halema, who lost four sons that night to Boko Haram’s gunmen, not surprisingly remain traumatised by their ordeal.

How do they feel now towards Boko Haram, I asked them both. There was a pause for what seemed an eternity before Naomi spoke again.

“I cannot even bear to hear the name mentioned it’s so painful and makes me cry,” she finally replies, her eyes glazing over with tears.