Iraqi Kurdish fighters flashed victory signs as they swept across the northern side of Sinjar mountain on Saturday, two days after breaking through to free hundreds of Yazidis trapped there for months by Islamic State fighters.A Reuters correspondent, who arrived on the mountain late Saturday, witnessed Kurdish and Yazidi fighters celebrating their gains after launching their offensive on Wednesday with heavy US air support.The Iraqi Kurdish flag fluttered, with its yellow sun, and celebratory gunfire rang out. Little children cheered "Barzani's party," in reference to the Kurdish region's president, Massoud Barzani."We have been surrounded the last three months. We were living off of raw wheat and barley," said Yazidi fighter Haso Mishko Haso.It was the plight of those trapped on the mountain, together with Islamic State's advance towards the Kurdish capital Arbil, that prompted US President Barack Obama to order air strikes against IS in Iraq in August. Thousands of members of the Yazidi religious minority were killed or captured by the militants.Since then, Kurdish peshmerga forces in northern Iraq have regained most of the ground they had lost. But the war grinds on, as a weakened Iraqi army and Shi'ite militia volunteers battle back and forth with Islamic State across central and western Iraq. The United States is also carrying out air strikes on IS in Syria.Kurdish and Yazidi fighters on Saturday predicted the Yazidi town of Sinjar to the south would soon fall to Kurdish forces. They said a battle there was already under way, although there was no independent confirmation.