Four days after Islamic State fighters were routed from the town of Ba’aj, Shia militia forces discover suicide belts and remnants of sharia bureaucracy – but no sign of the terror group’s leader

At the heart of the town that had sheltered him, Abu Bakr al-Baghdadi’s presence still lurked in ransacked files and ruined buildings. It had been four days since the Islamic State fighters had fled Ba’aj, taking with them all they could as they headed for a last stand in the deserts of Syria. But despite their haste, the fleeing extremists left behind clues to how much this small, forsaken corner of north-western Iraq mattered to the world’s most dangerous terror group, and its fugitive leader.

Inside a yellow wrought-iron gate, a suicide belt was left by a wall. In the room to the right, assault rifles, makeshift bombs, fuel and duct tape littered a floor slick with gasoline. On the other side of the barrier was a small office where a dog-eared Isis flag was displayed above two suicide vests on a fake tiger-skin couch. Files were scattered across a desk – instructions on how to treat sex slaves, how to dress and how to behave. Some invoked Baghdadi’s name.

Half the house was a bomb factory, the other half the terror organisation’s main administration centre, where fines were issued, bills paid, and identification cards confiscated. Whoever came to this nondescript building – willingly or otherwise – could not have escaped an indoctrination that controlled nearly every aspect of people’s lives. Books eulogising martyrdom were scattered among the detritus, alongside personnel records and photographs of new recruits and men and boys already lost to jihad.

Long held up as an icon of Isis’s strength, Ba’aj is now a symbol of its precipitous decline. Every village between the town and the Syrian border has been overrun in the past nine days by Shia militia forces allied to the Iraqi government, who are moving quickly to set up bases in the town.

To the east, communities that were deemed to be at the northernmost edge of Baghdadi’s crumbling caliphate have also been emptied and looted. Not a single resident has been allowed to stay in any of the conquered villages between Mosul and the frontier. In the last week, Iraq’s newest refugees have scattered across the desert plains, some in clapped-out cars and livestock trucks, some on foot, and others riding giant farm harvesters along the verges of ruined highways.

Facebook Twitter Pinterest A member of the Asa’ib Ahl al-Haq militia carefully handles a seized Isis suicide belt found in Ba’aj, northern Iraq. Photograph: Cengiz Yar/The Guardian

Giant clouds of dust caked the faces of the exodus. Near Qayyarah, south of Mosul, women and girls who had seen little daylight for three years slumped in the back of trucks, exhausted after a seven-hour journey along rutted roads and fields. They eschewed the black abayas, robes, that were mandatory under Isis for dresses of pink, blue and yellow – vivid splashes of colour against a dusky sky. Tens of thousands of sheep and cows trailed behind, shrouded in haze from one side of the horizon to the other.

“The Shias told us it is too dangerous to stay,” said one man who had stopped to drink water as the Ramadan fast ended. “They said there were bombs everywhere and that everyone must leave.”

The exiles from Ba’aj said they had learned not to ask questions about the terror leader who purportedly lived among them. “It was too dangerous to go looking, or even to raise the subject,” said one trader, Sobhe Mohammed. “He had around 10 safe houses,” said another man, who refused to be identified. “That we knew, but no-one was brave enough to ask where.”

Intelligence agencies tracking Baghdadi are certain that he spent much of the last two years in Ba’aj, and was there as recently as March. Twenty miles to the north, Iraqi Kurdish forces at the forefront of the hunt are confident that their quarry left the town long before it fell to the militias of the Popular Mobilisation Front (PMF), whose rapid sweep across north-western Iraq has changed the face of the war with Isis. And they are equally sure that he recuperated in Ba’aj from near-fatal injuries caused by an airstrike in February 2015.

Facebook Twitter Pinterest Suicide vests were left behind in the former Isis command centre in Ba’aj. Photograph: Cengiz Yar/The Guardian

Abu Mahdi al-Muhandis, a joint leader of PMF forces, said he was confident that senior Isis leaders had fled for Syria early last week. “We were chasing them west of Shawqat,” he told the Guardian. “They sent five or six suicide bombers at us and we have information that they were trying to get their important people and their families across the border. It was a very heavy fight and it seems that they were trying to clear the road.”

Five days before Isis finally fled Ba’aj, commanders ordered the group’s fighters to withdraw with their weapons into the Syrian towns of Mayedin and Dishasha. The capitulation leaves only two areas in northern Iraq, Hawija and Tal Afar, remaining under Isis control.

“Look how quickly they ran from here,” said Dr al-Khafaf, an emergency medic who had moved into Ba’aj hospital as soon as Isis moved out. “We were not expecting it to be so sudden. Ever since, he and other medics have had to pick their way through a hospital littered with improvised explosives. Above him, Isis had written a warning to female visitors, which read: “Your attention please. Please abide by the sharia dress code, or there will be consequences.”

“We defused eight bombs already,” said another medic, pointing at a discarded device on a chair in the foyer. He escorted us to another room ravaged by an explosion. “A dog walked inside here and triggered the bomb. Hold your nose.”

Booby traps and mines are a persistent danger in all areas vacated by Isis, but particularly Ba’aj. “We have defused more than 900 in the past few days alone,” said the leader of the PMF’s bomb disposal team, Abu Shams. “There are many more on the highway and roads.”

Facebook Twitter Pinterest Partially cut Iraqi ID cards were found by the PMF forces. It is suspected that Isis destroyed the cards to indicate that residents in Ba’aj were no longer Iraqis, but citizens of Islamic State. Photograph: Cengiz Yar/The Guardian

From a side road in the middle of town, three apparitions emerged through the haze. One wore a Muslim prayer cap, the two others clutched suicide belts. All wore military fatigues. “Who are you guys?” asked a nervous PMF soldier standing guard.

“We are Asa’ib [Ahl al-Haq, a powerful member of the PMF]. And we just found these suicide belts.”

One of the men lit a cigarette as he scraped through the explosive paste in the belt he was wearing. His other hand held a detonator attached to it. “It is disabled, you know,” he offered as reassurance. “Don’t go down that road, they have wired houses with hoses.”

The only tools the men seemed to have between them were a pair of red wire cutters. They shrugged with a fatalistic sense of duty and set off down another road riddled with rubble from airstrikes and hidden bombs left behind by the vanquished. “Don’t call us Isis; we’re Asa’ib,” said one of the trio, before they vanished into more ruins.

Between Ba’aj and the border, all that remains of Isis are the traps they left behind to slow the advancing victors. The town itself remains one of the most booby-trapped parts of Iraq and will take many weeks yet to yield all its secrets. The forces securing the town doubt they will need to look too far – once the bombs are defused. “He was here,” Abu Shams said of Baghdadi. “I can feel it.”

Additional reporting: Salem Rizk, Mohammed Rasool