The main US-backed and Kurdish-led force in northeastern Syria said Friday it lost nine fighters, including a commander, when two helicopters crashed this week in neighboring Iraq. The Syrian Democratic Forces said the helicopters crashed during bad weather while en route to the northern Iraqi city of Sulaymaniyah on Wednesday night. The nine killed included elite fighters, the group said. The statement added that the Syrian Kurdish fighters were in Iraq as part of an “exchange of expertise” in the fight against the ISIS group. It identified the killed commander as Sherfan Kobani, a cousin of SDF's top commander, Mazloum Abdi. The SDF did not elaborate on the cause of the crash or provide further details. The group called on local authorities in Iraq to hand over the nine bodies so they could be brought home for burial in Syria. The SDF has been a main force in the fight against the ISIS in Syria and still carries out operations against the extremists. ISIS once controlled large parts of Syria and Iraq under the extremists’ so-called “caliphate” and still has sleeper cells in the region. The militants frequently stage attacks, targeting Kurdish-led fighters in Syria, and also Iraqi forces and civilians in Iraq. The SDF statement is in sharp contrast to a report on Thursday from Iraqi Kurdish authorities, which said that only one helicopter — an AS350 Eurocopter — had crashed in Iraq’s Dohuk province in the northern semi-autonomous Iraqi Kurdish region. That report said that at least five people, including insurgents of Türkiye's outlawed Kurdistan Worker’s Party, or PKK, were on board. Zagros Hiwa, a PKK spokesperson, said Thursday the group does not possess helicopters and that the PKK was also investigating the crash. The PKK has been waging an insurgency against Türkiye since the 1980s and is considered a terrorist group by Ankara, the United States and the European Union. Its militants have established safe havens in northern Iraq and frequently come under attack by Türkiye in the region. Iraq’s government, the US-led coalition and Türkiye had all denied ownership of the helicopter.