"...hundreds of Christian families fled their homes in the northern city of Mosul...
The fighters, who have run the city after a military offensive that began six weeks ago, issued a written declaration to Mosul's Christian community to either convert, pay a tax, leave or face imminent execution.
Mosul's new rulers said there would be "nothing for them but the sword" if Christians did not abide by those conditions by Saturday.
...The Sunni-led Islamic State group issued the the ultimatum in a letter after Friday prayers.
...Mosul, Iraq's second largest city, was overrun by the Islamic State and allied rebel groups last month.
Prior to the 2003 US invasion, more than a million Christians lived in Iraq, including more than 600,000 in Baghdad and 60,000 in Mosul, as well as a substantial number in the oil city of Kirkuk and in Basra.
Until their forced exodus over the weekend, Christians had been continuously present in Mosul for approximately 16 centuries."