RAF planes have dropped essential supplies to aid refugees still trapped on Sinjar Mountain in northern Iraq, the Department for International Development has confirmed.

Previous attempts had to be aborted for fear that the drops would injure those on the ground. Reports have surfaced of US aid being destroyed on impact after being dropped from too great a distance.

Thousands of Iraqi civilians remain stranded on the mountain side after being driven from their homes by members of the Islamic State (IS) last week. Without access to food, water, medication or shelter, it's a struggle for survival – an Iraqi General told the Telegraph on Sunday: "It is death valley. Up to 70 per cent of them are dead."

Those seeking safety on the mountain are members of religious minority groups from the Sinjar city area, which has been taken over by IS.

Some are Christians and Muslims, but most are Yazidis – an offshoot from Zoroastrianism which blends ancient religious traditions with both Christianity and Islam. Members of this minority faith have been targeted relentlessly by IS insurgents, who believe them to be "devil-worshippers".

The US began airstrikes in the region this week to secure Kurdistan, though President Obama has repeatedly stressed that these will be "limited".

"As commander in chief, I will not allow the United States to be dragged into another war in Iraq," he declared.

The UK's Ministry of Defence has ruled out active combat, but Downing Street said yesterday that the trapped civilians are its "immediate priority".

The BBC reports that the UK government has also said it will work with international representatives in the Kurdish region "to mitigate safety concerns".