U.S. President Barack Obama said Thursday he has approved targeted air strikes in Iraq, near the site where some 40,000 religious minorities are trapped on a mountaintop after fleeing from Islamic State militants who have threatened to kill them.

Obama said the Iraqi government asked for U.S. help in fighting Islamic State militants, who have surged across northern Iraq in the country's Kurdish region, forcing tens of thousands of Christians and Yazidis — a Kurdish ethno-religious community — to leave their homes or risk death.

Many have fled into the mountains near the town of Sinjar, where Obama said they are trapped without food and water and are facing "genocide."

A relative mourns as he carries the coffin of a Kurdish fighter who was killed during clashes with Islamic State fighters in the Iraqi city of Rabia. (Rodi Said/Reuters) "America is coming to help," Obama said during a news conference in the White House dining room.

He also said the U.S. military had already carried out airdrops of humanitarian aid in the area.

Speaking after meetings with his national security team, Obama — in his most significant response to the Iraq crisis — U.S. air power could also be used to protect American personnel if the militants advance toward the Kurdish capital Arbil, where they are based.

The airstrikes would be the first carried out by the U.S. military in Iraq since the withdrawal of its forces at the end of 2011, but Obama insisted he would not commit any ground forces and had no intention of letting the United States get dragged back into a war there.

UN holds special meeting on Iraq

Displaced people from the minority Yazidi sect, fleeing the violence in the Iraqi town of Sinjar west of Mosul, sought refuge in Iraq's Dohuk province on Thursday. (Ari Jalal/Reuters) Earlier Thursday, The UN Security Council condemned the attacks by the Islamic State group and called for international support for Iraq after the 15-member body held an emergency meeting on the situation.

"The members of the Security Council call on the international community to support the government and people of Iraq and to do all it can to help alleviate the suffering of the population affected by the current conflict in Iraq," said Britain's UN Ambassador Mark Lyall Grant, president of the council for August.

Reuters photographs showed what appeared to be Islamic State fighters controlling a checkpoint at the border area of the Kurdish semi-autonomous region, little over 30 minutes' drive from Arbil, a city of 1.5 million that is headquarters to the Kurdish regional government and of many businesses.

The fighters had raised the movement's black flag over the guard post. However a Kurdish security official denied that the militants were in control of the Khazer checkpoint, and the regional government said its forces were advancing and would "defeat the terrorists", urging people to stay calm.

Earlier this week, the militants captured Iraq's biggest Christian town, Qaraqosh, prompting many residents to flee, fearing they would be subjected to the same demands the Sunni militants made in other captured areas — leave, convert to Islam or face death.

The Islamic State, considered more extreme than al-Qaeda, sees Iraq's majority Shias and minorities such as Christians and Yazidis, a Kurdish ethno-religious community, as infidels.

Sinjar situation

The militants' capture of the town of Sinjar last weekend, ancestral home of the Yazidis, prompted tens of thousands of people to flee to surrounding mountains.

Some of the many thousands trapped on Sinjar mountain have been rescued in the past 24 hours, a spokesman for the UN Office for the Co-ordination of Humanitarian Affairs said, adding that 200,000 in total had fled the fighting.

Iraq was rocked by violence in Mosul and Baghdad on Thursday, while Obama threatened air strikes if Islamic State fighters continued their march toward Arbil. (CBC) "This is a tragedy of immense proportions, impacting the lives of hundreds of thousands of people," spokesman David Swanson said by telephone.

Many of the displaced people urgently need water, food, shelter and medicine, he said. A spokesman for the UN agency for children said many of the children on the mountain were suffering from dehydration and at least 40 had died.

Yazidis, seen by the Islamic State as "devil worshippers", risk being executed by the Sunni militants seeking to establish an Islamic empire and redraw the map of the Middle East.

Thousands of Iraqis, most of them Yazidis, are streaming to the border with neighbouring Turkey to flee the fighting, Turkish officials said.

The plight of fleeing Christians prompted Pope Francis to appeal to world leaders to help end what the Vatican called "the humanitarian tragedy now under way" in northern Iraq.