Tens of thousands of Iraq's Yazidi minority have fled their homes after militants from the extremist Islamic State of Iraq and Syria captured their towns, a spokesman for the community said, according to the Associated Press.
Almost 40,000 Yazidis have left their homes in the towns of Sinjar and Zumar north of Iraq to seek refuge in the neighboring semi-autonomus Kurdish region, Jawhar Ali Begg, the spokesman, said.
He says the militants gave the Yazidis an ultimatum to convert to Islam on Sunday, pay a tax or flee their homes or they will be killed, Al Arabiya reported.
Begg also told The Associated Press that "thousands of Yezidi people have been killed" in the onslaught by the Islamic State group.
The Islamic State has seized a large area straddling the Iraqi-Syrian border and declared their own, self-styled caliphate.
Earlier on Sunday, ISIS fighters took over Iraq's biggest dam unopposed by Kurdish fighters, witnesses said, according to Reuters news agency.
Control of the dam could give ISIS, which has threatened to march on Baghdad, the ability to flood major cities.
ISIS fighters, who had already been running large swathes of neighboring Syria, launched a blistering offensive on June 9 that saw the capture of Mosul, Iraq's second-largest city, and move into much of the country's Sunni heartland.
Earlier in July, Christians fled Mosul en-masse after the al-Qaeda-inspired extremist group issued an ultimatum similar to the one issued for the Yezidi community in northern Iraq.