Iraqi Kurdish security forces have opened a road to Sinjar Mountain in northwestern Iraq, rescuing more than 5,000 Yazidis trapped there after running away from fighters from the Islamic State (IS) group, a Kurdish army spokesman has told Al Jazeera.

"I can confirm that we succeeded in reaching the mountains and opening a road for the refugees," said Halgord Hikmet, a spokesman for the Peshmergas, the Kurdish security forces.

Hikmet said that recent air strikes on IS targets by US warplanes had allowed the Peshmergas to open a route to the mountain.

The IS, which has captured large areas of Syria and Iraq, see Shia Muslims and minorities such as Christians and Yazidis, a Kurdish ethno-religious community, as infidels.

The Yazidis, a minority that follow a 4,000-year-old faith, had taken cover in Sinjar Mountain for the past five days in searing heat, and with no supplies, after fleeing advancing IS fighters.

Two Kurdish officials, Ekrem Hasso and Juan Mohammad, told the AP news agency that the Yazidis fled across the border from Iraq to seek refuge with the Kurds of northeastern Syria.

Rami Abdel-Rahman, who heads the London-based Syrian Observatory for Human Rights, also said thousands of people have fled from Iraq into Syria but had no exact number.

US warplanes have launched several waves of air strikes against IS fighters in northern Iraq since Friday.

Aerial drones and F-18 jets have attacked fighter positions close to the Kurdish capital of Erbil.

The air strikes seek to allow the federal and Kurdish governments to claw back areas lost in two months of conflict.

On Friday and Saturday, the US also dropped food and water for the Yazidis hiding on Sinjar Mountain. The UK is also delivering aid and has announced it is sending medics to northern Iraq.

'US troops will not fight in Iraq'

Barack Obama, the US president, said at a news conference on Saturday that Washington was proud to be acting alongside friends and allies in Iraq during the air strikes and was in the process of reaching Iraqi civilians trapped on Sinjar Mountain.

Obama repeatedly called on the Iraqis to come together to form a legitimate Iraqi government and overcome a political crisis that has been going on for months.

He also said that there was no particular timetable regarding the air strikes, adding that they would take place as long as it was necessary to protect Iraqi civilians and US citizens, diplomats and military advisers in Iraq.

Separately, in his weekly address earlier on Saturday, he said he would not allow the US to be dragged into another war in Iraq, making it clear that American combat troops will not return to fight there.

The air strikes are the first in the embattled country since Obama put an end to the US occupation in 2011 and come after the IS group made massive gains on the ground, seizing a major dam and forcing a mass exodus of religious minorities.