Mount Sinjar stinks of death. The few Yazidis who have managed to escape its clutches can tell you why. "Dogs were eating the bodies of the dead," said Haji Khedev Haydev, 65, who ran through the lines of Islamic State jihadists surrounding it.
On Sunday night, I became the first western journalist to reach the mountains where tens of thousands of Yazidis, a previously obscure Middle Eastern sect, have been taking refuge from the Islamic State forces that seized their largest town, Sinjar.
I was on board an Iraqi Army helicopter, and watched as hundreds of refugees ran towards it to receive one of the few deliveries of aid to make it to the mountain. The helicopter dropped water and food from its open gun bays to them as they waited below. General Ahmed Ithwany, who led the mission, told me: "It is death valley. Up to 70 per cent of them are dead."
Two American aid flights have also made it to the mountain, where they have dropped off more than 36,000 meals and 7,000 gallons of drinking water to help the refugees, and last night two RAF C-130 transport planes were also on the way.
However, Iraqi officials said that much of the US aid had been "useless" because it was dropped from 15,000ft without parachutes and exploded on impact.
Handfuls of refugees have managed to escape on the helicopters but many are being left behind because the craft are unable to land on the rocky mountainside. There, they face thirst and starvation, as well as the crippling heat of midsummer.
Hundreds, if not more, have already died, including scores of children. A Yazidi Iraqi MP, Vian Dakhil, told reporters in Baghdad:
"We have one or two days left to help these people. After that they will start dying en masse."
The Iraqi Army is running several aid missions every day, bringing supplies including water, flour, bread and shoes.
The helicopter flights aim to airlift out refugees on each flight, but the mountains are sometimes too rocky to land on, meaning they return empty.
Even when it can land, the single helicopter can take just over a dozen refugees at a time, and then only from the highest point of the mountain where it is out of range of jihadist missiles. Barely 100 have been rescued in this way.
The flights have also dropped off at least 50 armed Peshmerga, Kurdish forces, on the mountain, according to Captain Ahmed Jabar.
Other refugees have made their way through Islamic State lines, evading the jihadists to reach safety, or travelling through
Kurdish-controlled sections of Syria to reach the town of Dohuk. So far the Yazidi refugees left behind have survived by hiding in old cave dwellings, drinking from natural springs and hunting small animals, but with families scattered across Mount Sinjar, a barren range stretching for around 35 miles near the border with Syria, there are fears aid will not reach them all unless the humanitarian relief operation is significantly stepped up .
Hundreds can now be seen making their way slowly across its expanse, carrying what few possessions they managed to flee with on their backs. Exhausted children lie listlessly in the arms of their parents, older ones trudging disconsolately alongside while the sun beats down overhead.
The small amount of relief the peshmerga militia can bring up into the mountain is not simply enough.
One pershmerga fighter, Faisal Elas Hasso, 40, said: "To be honest, there's not enough for everyone," he said. "It's five people to one bottle."
The refugees who made it out described desperate scenes as they awaited help from the outside world.
"There were about 200 of us, and about 20 of that number have died," said Saydo Haji, 28. "We can live for two days, not more."
Emad Edo, 27, who was rescued in an airlift on Friday at the mountain's highest point explains how he had to leave his niece, who barely had enough strength to keep her eyes open, to her fate.
"She was about to die, so we left her there and she died," he said.
Others shared similar stories. "Even the caves smell very bad," Mr Edo added. According to several of the airlifted refugees, the Geliaji cave alone has become home to 50 dead bodies.
Saydo Kuti Naner, 35, who was one of 13 Yazidis who snuck through Islamic State lines on Thursday morning, said he travelled through Kurdish-controlled Syria to get to Kurdistan.
He left behind his mother and father, too old to make the rough trip, as well as 200 sheep. "We got lucky," he said. "A girl was running [with us] and she got shot." He added that this gave enough cover for the rest of them to get away.
Mikey Hassan said he, his two brothers and their families fled up into Mount Sinjar and then managed to escape to the Kurdish city of Dohuk after two days, by shooting their way past the jihadists. Mr Hassan said he and his family went for 17 hours with no food before getting their hands on some bread.
The Yazidis, an ethnically Kurdish community that has kept its religion alive for centuries in the face of persecution, are at particular threat from the Islamists, who regard them as 'devil worshippers', and drove them from their homes as the peshmerga fighters withdrew.
There have been repeated stories that the jihadists have seized hundreds of Yazidi women and are holding them in Mosul, either in schools or the prison. These cannot be confirmed, though they are widely believed and several Yazidi refugees said they had been unable to contact Yazidi women relatives who were living behind Islamic State lines.
Kamil Amin, of the Iraqi human rights ministry, said: "We think that the terrorists by now consider them slaves and they have vicious plans for them."
Tens of thousands of Christians have also been forced to flee in the face of the advancing IS fighters, many cramming the roads east and north to Erbil and Dohuk. On Thursday alone, up to 100,000 Iraqi Christians fled their homes in the Plain of Ninevah around Mosul.
Refugees said the American air strikes on IS positions outside Erbil were too little, too late. They said they felt abandoned by everyone -- the central government in Baghdad, the Americans and British, who invaded in 2003, and now the Kurds, who had promised to protect them.
"When the Americans withdrew from Iraq they didn't protect the Christians," said Jenan Yousef, an Assyrian Catholic who fled Qaraqosh, Iraq's largest Christian town, in the early hours of
Thursday. "The Christians became the scapegoats. Everyone has been killing us."
The situation in Sinjar has irreparably damaged the notion of home for the Yazidis. For a large portion of them, the unique culture of the area will never return, and they will therefore have nothing to go back for.
"We can't go back to Sinjar mountain because Sinjar is surrounded by Arabs," said Aydo Khudida Qasim, 34, who said that Sunni Arab villagers around Sinjar helped Islamic State take the area. Now he as well as many of his friends and relatives want to get out of Iraq
altogether. "We want to be refugees in other countries, not our own," he said.
Additional reporting by Richard Spencer, Erbil.