Displaced families from the minority Yazidi sect fleeing the violence in the Iraqi town of Sinjar arrive at Dohuk province, Aug. 4, 2014. Reuters

The Islamic State of Iraq and Syria is notoriously hostile to Shiite Muslims, Kurds, Christians and other groups that don’t believe in its brand of fundamentalist Sunni Islam. But there is another, more obscure community in Iraq being targeted by ISIS: the Yazidi.

Who are the Yazidi?

Numbering about 700,000 worldwide, the Yazidi are a sect that combines elements of Islam and Zoroastrianism, the ancient Persian religion dating back to at least 600 B.C., according to the Theosophical Society of America.

What are the Yazidi’s beliefs?

While believing in one god, the Yazidi also believe in seven deities. The most important of these is Tawsi Melek, which translates to the “Peacock Angel" or "Peacock King," according to yeziditruth.org.

Where are the Yazidi?

In Iraq, where there are around 500,000 Yazidi, they largely live in the northern portion of the country, where ISIS has recently made gains by capturing the towns of Zumar and Sinjar. The ISIS advance led to as many as 200,000 Yazidis fleeing the area after they were given an ultimatum of converting to Islam, paying the "jizya" tax on nonbelievers, leaving or being killed.

Ethnically, the Yazidi are Kurdish, and are considered fellow Kurds by the Muslim Kurds who dominate northeastern Iraq. Islamic State fighters have been making advances against the Kurds' peshmerga troops.

There are smaller populations of Yazidi in Germany, Syria, Russia, Armenia and Georgia. Only about 500 Yazidi are living in the United States, according to the Joshua Project.

Why does ISIS brand the Yazidi as devil worshippers?

Another name for Tawsi Melek is Shaytan (i.e. Satan), the Arabic word for “devil” or “demon.” The Yazidi are aware of this translation, and it’s the reason why they don’t utter this alternative name for their deity for fear of being killed.

Is anything being done to help the Yazidi?

The Yazidi are trying to raise awareness about their suffering in Iraq. Their leader, Prince Taheen, has requested in an “urgent distress call” to Iraqi and world leaders “for aid and to lend a hand and help the people of [the] Sinjar areas and its affiliates and villages and complexes, which are home to the people of the Yazidi religion,” according to the Chicago-based Assyrian International News Agency. The Assyrian Christians are another ancient people in the region being targeted by ISIS.

“Citizens of this religion are peaceful people who acknowledge all principles and humanitarian values and respect all religions, and never had enmity against any of their countrymen, and in the near past they even had a major humanitarian stand with their fellow [residents] of Mosul and Tal Afar, and today they desperately need their brethren's help,” the prince continued, referring to ISIS wresting control of those cities from Iraqi government forces in June. “This humanitarian appeal I make on my behalf and on behalf of the people of this religion to come to their assistance and help the Yazidi people as soon as possible.”

Iraqi President Fuad Masum said it was “the collective responsibility of all Iraqis to assist the displaced” from Sinjar and Zumar and “expressed particular concern over the fate of the minority Yazidi community,” according to a U.N. press release from Sunday.

Prime Minister Nouri al-Maliki has sent the Iraqi air force to fight ISIS in northern Iraq, which would indirectly help the Yazidi, who have warm relations with their Kurdish neighbors. And the United States is also sending military aid to the Kurds, albeit covertly, according to the New Yorker.