President Obama is considering options to assist trapped minorities in Iraq, including possible airstrikes and airdrops of food and medicine, a government official said.

The administration has been mulling options for weeks, but the issue has come to a head with a mounting humanitarian catastrophe in northern Iraq where the Yazidis, a small religious minority, are trapped on a mountain top surrounded by Islamic militants.

The source asked not to be named since he was not authorized to speak about the issue. No final decision has been made.

White House spokesman Josh Earnest has said the administration is working with Iraqi and Kurdish officials on efforts to address a looming "human catastrophe," but he did not provide specifics.

The Yazidis are a tiny religious group that were forced to flee their homes when militants attacked Sinjar in northern Iraq. The militants consider the Yazidis as apostates.

Tens of thousands of refugees fled into the mountains, perhaps hoping to reach the Kurdish region in the north, but were trapped because of militant activity between the mountain and the Kurdish area, and are running short on food and water.

Iraqi aircraft have attempted to air drop supplies to the Yazidis but with limited success. Dropping supplies, particularly on a mountain top, is difficult as packages of food and water break open on impact.

The U.S. Air Force has extensive experience with air dropping supplies, which they regularly do in the mountains of Afghanistan with accuracy.

Air strikes could be used to blunt the battlefield successes of the militants, which now control about one-third of Iraq's territory....

The 40,000 Iraqis stranded on a mountain and facing possible genocide at the hands of surrounding Islamic State fighters are the last surviving community in their ancestral homeland of the Yazidis, long misunderstood by the outside world as "Devil-worshippers".

One of the most persecuted minorities in the Middle East, the Yazidis in fact find even the mention of the word "Satan" profoundly offensive, and have kept their ancient religion alive despite centuries of oppression.

The Yazidis mark themselves out as different. They never wear the colour blue. They are not allowed to eat lettuce. Many of the men wear their hair in long plaits that make them resemble nothing so much as Asterix and Obelix.

They believe one of their holy books, the Black Book, was stolen by the British in colonial times and is being kept somewhere in London.

But in their home town of Sinjar, from where they have now fled to the mountains above, they were welcoming in a way that belied their fearsome reputation as Satanists.

For ordinary Iraqis, they are bogeymen to frighten children with. But for religious extremists through the centuries, they have been Devil-worshippers to be slaughtered.

The misidentification came about because the Yazidis worship a fallen angel, the Malek Tawwus, or Peacock Angel. But, unlike Lucifer, the Yazidis' fallen angel was forgiven by God and restored to heaven.

Their religion is not just an offshoot of Christianity or Islam. They do not believe in heaven or hell, but in reincarnation, which they describe as the soul "changing its clothes".

They have kept their religion alive through the Talkers, men who are taught the entire text of their missing holy book by memory as children, and who in turn pass it on to their own sons....

There are darker sides to the Yazidis. They have a tradition of killing any of their members who leave the religion, and 2007 it was reported that Du'a Khalil Aswad, a Yazidi woman, was stoned to death for converting to Islam and marrying a Muslim man....