Iraq's human rights minister Mohammed Shia al Sudani announced Sunday that at least 500 Yazidis been killed and about 300 had been kidnapped by the Islamic State of Iraq and the Levant or ISIL. Some of those who were killed were buried alive, and women and children were among those kidnapped and taken into slavery.

Yahoo News reported that the Yazidis are an ethnic minority group residing primarily in northern Iraq. Their beliefs predate Islam and was developed in ancient Persia in 1,500 B.C. Overtime the religion has adopted elements of Christianity Islam and Judaism. ISIL had referred to the Yazidis as devil worshipers and, earlier this week, threatened that they convert to Islam by midday Sunday or die.

According to Gulf News, the insurgents move through northern Iraq has forced tens of thousands to leave there homes and has threatened the region and provoked the first airstike form the U.S. since their troops were withdrawn from Iraq in 2011.

"We have striking evidence obtained from Yazidis fleeing Sinjar and some who escaped death and also crime scene images that show indisputably that the gangs of the Islamic States have executed at least 500 Yazidis after seizing Sinjar," Sudani told Reuters.

"Some of the victims, including women and children, were buried alive in scattered mass graves in and around Sinjar."

President Obama spoke about dealing with the ISIL on Saturday saying that it was a "long-term project."

"There is no doubt that their advance, their movement over the last several months has been more rapid than the intelligence estimates and I think the expectations of policy makers both in and outside of Iraq," Obama said.

"Part of that is not a full appreciation of the full degree to which the Iraq security forces, when they are far away from Baghdad, did not have the incentive or capacity to hold ground against an aggressive adversary."

The U.S. has also dropped relief supplies to tens of thousands of Yazidis who had gathered on top of Mount Sinjar to seek shelter from the violence.

Pope Francis held a silent prayer at the Vatican fro the victims of the Iraqi conflict, who included Christian minorities, in his weekly address on Sunday.

"Thousands of people, among them many Christians, banished brutally from their houses, children dying of hunger and thirst as they flee, women kidnapped, people massacred, violence of all kinds," he said.

"All of this deeply offends God and deeply offends humanity."