Kurdish forces celebrated in the battle-ravaged streets of Sinjar on Friday evening after retaking the northern Iraqi town from Islamic State (IS) jihadists and ending 15 months of vicious occupation.

Fighters from the Kurdistan Regional Government (KRG), known as peshmerga, had reached the central square by mid-morning on the second day of a major offensive that apparently encountered little resistance. A few hours later, a group of young gunmen shuddered past the remains of abandoned houses and shops in a captured IS suicide bomb truck — a large American-made pickup clad in makeshift armor and still carrying remnants of its intended explosive cargo — on an impromptu victory parade.

The vehicle would have been designed to blast through Kurdish lines, but instead, two peshmerga stood up in the bed as it drove, yelling jubilantly as one fired his Kalashnikov into the air. The surrounding streets were strewn with burnt-out, bullet-riddled vehicles and draped in fallen phone lines and electricity cables. An unexploded mortar shell was lodged in the concrete of a side road and another lay on a nearby pavement.

A Kurdish fighter atop a ruined building in Sinjar. (Photo by John Beck)

The Kurdistan Workers' Party (PKK) and Syrian People's Protection Units also took part in the offensive, as did militias drawn from members of the Yazidi religious minority, which made up of much of Sinjar's population before IS overran it in August 2015. The extremist militants regard Yazidis as apostates and "devil worshippers," and massacred hundreds of men and took women as sex slaves when they seized the town.

Tens of thousands of people fled. Many were trapped up Mount Sinjar — which rises from the town's outskirts — creating a desperate humanitarian crisis that eventually prompted international intervention in the form of US airstrikes on IS and supply drops of food and water.

On the roof of an abandoned school, one Yazidi peshmerga member prayed as the sun set and then playfully kicked a soccer ball around with a comrade. Watching, another described the recent fighting. "At night there were bombs here, here, and here," he said, gesturing to ruined buildings. "But that's over now," he added with a smile.

A Yazidi peshmerga fighter prays on the rooftop of a Sinjar school. (Photo by John Beck)

Signs of IS brutality remained in Sinjar even after their retreat. Yazidi members of the Iraqi police pointed out sites such as the residency office and former hospital where they said female slaves had been held. They refrained from entering buildings for fear that they were rigged with explosives. The jihadists likely left behind booby traps and IEDs when they pulled back, so the Kurdish fighters picked their way around the town, keeping to the center of roads.

The cleanup operation was well underway by Friday evening, and a crudely equipped bomb squad wielding a mine detector and pliers strode down a street newly cleared of rubble by a procession of bulldozers.

Peshmerga fighters brew tea in Sinjar. (Photo by John Beck)

A few civilians had already returned in order to find out what was left of their homes, but few had been left intact. Lines of vehicles had already begun to form at the outside of the perimeter zone set up by peshmerga before the offensive began. Further up the mountain, children cheered as convoys of Kurdish and Yazidi fighters passed. A group of armed Westerners wearing insignia-less combat looked on. US spec ops personnel provided tactical support to the peshmerga during the offensive and helped direct airstrikes, the Pentagon said Thursday.

The offensive began on Wednesday night, and involved 7,500 peshmerga fighters affiliated with the Kurdistan Democratic Party (KDP), along with the PKK, YPG, and Yazidi units. The US-led anti-IS coalition provided air support, and victory came fast, with IS seemingly withdrawing southwards without putting up any meaningful defense, leading to suspicions that the group had pulled out the bulk of its forces some time previously.

KRG president Masoud Barzani speaking on Mount Sinjar. (Photo by John Beck)

It was a dramatic change of fortune. In August 2014, the peshmerga retreated in disarray when IS moved on Sinjar, leaving the PKK and YPG to help thousands of Yazidis escape.

This rout was a major embarrassment that the KRG have been keen to redress, but a December assault only retook around a quarter of the town, then stalled. Coalition airstrikes have continued on IS positions there though, and the peshmerga had been moving to block the group's access routes.

Taking control of Sinjar will have significant strategic value, commanders say, cutting IS supply lines between Iraq's second city of Mosul, which it overran in June 2014, and Raqqa in Syria, the capital of its self-proclaimed caliphate.

Walking down the center of the road for safety. (Photo by John Beck)

KRG president Masoud Barzani held a press conference on Friday afternoon, in which he announced a successful conclusion to the offensive and thanked the coalition for its air support. He went on to say that the peshmerga were responsible for the victory and had been the only force involved and added that he hoped Sinjar could become its own province within the KRG, a proposition unlikely to be be popular with the central government in Baghdad.

But the PKK disputed his version of events. Sarhad, the group's commander in Sinjar told VICE News that his fighters had been first to enter Sinjar during the attack and that the peshmerga had only joined later. PKK fighters made similar claims when peshmerga retook ground from IS last year.

A peshmerga fighter plays soccer in Sinjar. (Photo by John Beck)

"We had already gone inside the the city, but the peshmerga came after us and they want their flag to be in the city again," he said, adding that IS had been driven out of the area between Sinjar and Syria purely by the YPG and PKK — which is designated a terrorist group by Turkey and the US — and that it remains under their control.

He dismissed the KRG president's claims as politics. "Barzani is saying what he wants for his party," he added. "[But] the Yazidis were left by peshmerga [in August 2015] then killed and captured by IS. It was those same peshmerga who are in the city today."