By . David Williams . and Tom Mctague . Desperate, starving families watched yesterday as the RAF was forced to abort an operation to drop emergency supplies. A C130 cargo plane had been due to make a second drop of UK aid on the slopes of the Iraqi mountain where tens of thousands of Yazidis and Christians are trapped in appalling conditions. But despite making several passes, the Hercules could not find a clear space to parachute aid bundles down without risking injury to those below. Scroll down for video . Displaced Iraqis from the Yazidi community gather for humanitarian aid at the Iraq-Syria border at Feeshkhabour border point on Sunday . Thousands are still trapped on Mount Sinjar in northern Iraq after fleeing the advance of Islamic State militants. Another . humanitarian flight will come early today as British and US special . forces, with Kurdish fighters, try to plot an escape route for up to . 150,000 refugees. Some . 20,000 are said to have been led off the mountain in the past 48 hours, . many making their way to the Kurdish city of Irbil where the 1.5million . population has grown by around 185,000. There . were heartbreaking scenes yesterday as thousands who had been trapped . on the mountain, or who had fled into neighbouring Syria, tried to reach . safety in Kurdish areas across a pontoon bridge. People . scanned every vehicle for loved ones. Unknown numbers of men, women and . children went missing in the chaos as panicked Yazidis fled militants. Others . were lost as families scattered under gunfire from extremists chasing . them into the mountains. Dizzy from thirst, adults lost track of . children in the crowds on Mount Sinjar. Some . women were abducted by Islamic State militants, and Iraqi and US . officials say they believe hundreds are being held captive. ‘There are many missing, many,’ said Naji Khano, who lost his son Sherwan, 17, as he fled gunmen. At . the Semalka crossing, trucks, Jeeps and cars full of Yazidis inched . across the pontoon bridge over the Tigris River, which forms the border . between Syria and the relative security of Kurdish Iraq. 'My sister is missing. We ran everywhere, we were terrified. We lost each other' Amer Qassem . Hundreds . milled among them on foot, some barefoot, lips cracked from thirst, . clutching water bottles, watermelons and flat bread loaves distributed . by aid workers. Men walked into the river to cool off; mothers bathed . their children. One woman . walked weeping; a boy held her hand. Most said they had not eaten in . days. Many spoke of the dead they had left behind, some shot by . militants, others dead from starvation or dehydration on the mountain. ‘My sister is missing,’ 22-year-old Amer Qassem said. He . and dozens of his extended family fled their village of Tel Qassab on . the night of August 2 when they heard Islamic State fighters were . approaching. UK . aid was dropped on northern Iraq on Saturday, but a second attempt had . to be abandoned early this morning amid fears for the safety of the . crowd of refugees below . As the sun rose, militants riding a Jeep mounted with a machine gun spotted them and opened fire. ‘We . ran everywhere, we were terrified. We lost each other,’ Qassem said. As . the family regrouped, they realized around ten women were missing. 'With a number of people at the drop sites this morning, the crew made the responsible decision not to carry out the air drop to ensure that the lives of those in the area would not be put at risk' RAF spokesman . ‘My sister Amira was one of them,’ he said. ‘My father is a broken man now, he does not know what to do.’ The . US yesterday launched more air strikes on vehicles and mortars around . Irbil in an effort to blunt the militants’ advance and protect American . personnel around the Kurdish capital. US warplanes and drones have attacked militants firing on minority Yazidis around Sinjar in the far west of Iraq. Yesterday, . concerned at Islamic State’s huge gains near both Baghdad and Irbil, . the US also moved to supply Kurdish fighters with weapons. Humanitarian aid was loaded onto a RAF Hercules C130 at RAF Brize Norton for Iraq on Friday. Supplies included drinking water and tents . Officials . would not say which US agency is involved or what weapons are being . sent, but one said it was not the Pentagon. The CIA has historically . undertaken similar operations. Previously, . the US had insisted on only selling arms to the Iraqi government in . Baghdad, but the Kurdish peshmerga fighters have been losing ground to . Islamic State in recent weeks. However, . they yesterday claimed to have recaptured Gwer and Makhmur, towns near . Irbil, by moving forward rapidly after US air strikes. As . those on the mountain prepared to spend a seventh night in the open . air, an RAF spokesman stressed: ‘The safety of the Yazidi community is . paramount. ‘With a number . of people at the drop sites this morning, the crew made the responsible . decision not to carry out the air drop to ensure that the lives of those . in the area would not be put at risk.’
C130 cargo plane had been due to make a second drop of UK aid in Iraq .
Tens of thousands of Yazidis and Christians trapped in horrific conditions .
Hercules could not find clear space to safely parachute down aid bundles .
Another humanitarian flight expected to come early today on Mount Sinjar .
By . David Williams . and Tom Mctague . Desperate, starving families watched yesterday as the RAF was forced to abort an operation to drop emergency supplies. A C130 cargo plane had been due to make a second drop of UK aid on the slopes of the Iraqi mountain where tens of thousands of Yazidis and Christians are trapped in appalling conditions. But despite making several passes, the Hercules could not find a clear space to parachute aid bundles down without risking injury to those below. Scroll down for video . Displaced Iraqis from the Yazidi community gather for humanitarian aid at the Iraq-Syria border at Feeshkhabour border point on Sunday . Thousands are still trapped on Mount Sinjar in northern Iraq after fleeing the advance of Islamic State militants. Another . humanitarian flight will come early today as British and US special . forces, with Kurdish fighters, try to plot an escape route for up to . 150,000 refugees. Some . 20,000 are said to have been led off the mountain in the past 48 hours, . many making their way to the Kurdish city of Irbil where the 1.5million . population has grown by around 185,000. There . were heartbreaking scenes yesterday as thousands who had been trapped . on the mountain, or who had fled into neighbouring Syria, tried to reach . safety in Kurdish areas across a pontoon bridge. People . scanned every vehicle for loved ones. Unknown numbers of men, women and . children went missing in the chaos as panicked Yazidis fled militants. Others . were lost as families scattered under gunfire from extremists chasing . them into the mountains. Dizzy from thirst, adults lost track of . children in the crowds on Mount Sinjar. Some . women were abducted by Islamic State militants, and Iraqi and US . officials say they believe hundreds are being held captive. ‘There are many missing, many,’ said Naji Khano, who lost his son Sherwan, 17, as he fled gunmen. At . the Semalka crossing, trucks, Jeeps and cars full of Yazidis inched . across the pontoon bridge over the Tigris River, which forms the border . between Syria and the relative security of Kurdish Iraq. 'My sister is missing. We ran everywhere, we were terrified. We lost each other' Amer Qassem . Hundreds . milled among them on foot, some barefoot, lips cracked from thirst, . clutching water bottles, watermelons and flat bread loaves distributed . by aid workers. Men walked into the river to cool off; mothers bathed . their children. One woman . walked weeping; a boy held her hand. Most said they had not eaten in . days. Many spoke of the dead they had left behind, some shot by . militants, others dead from starvation or dehydration on the mountain. ‘My sister is missing,’ 22-year-old Amer Qassem said. He . and dozens of his extended family fled their village of Tel Qassab on . the night of August 2 when they heard Islamic State fighters were . approaching. UK . aid was dropped on northern Iraq on Saturday, but a second attempt had . to be abandoned early this morning amid fears for the safety of the . crowd of refugees below . As the sun rose, militants riding a Jeep mounted with a machine gun spotted them and opened fire. ‘We . ran everywhere, we were terrified. We lost each other,’ Qassem said. As . the family regrouped, they realized around ten women were missing. 'With a number of people at the drop sites this morning, the crew made the responsible decision not to carry out the air drop to ensure that the lives of those in the area would not be put at risk' RAF spokesman . ‘My sister Amira was one of them,’ he said. ‘My father is a broken man now, he does not know what to do.’ The . US yesterday launched more air strikes on vehicles and mortars around . Irbil in an effort to blunt the militants’ advance and protect American . personnel around the Kurdish capital. US warplanes and drones have attacked militants firing on minority Yazidis around Sinjar in the far west of Iraq. Yesterday, . concerned at Islamic State’s huge gains near both Baghdad and Irbil, . the US also moved to supply Kurdish fighters with weapons. Humanitarian aid was loaded onto a RAF Hercules C130 at RAF Brize Norton for Iraq on Friday. Supplies included drinking water and tents . Officials . would not say which US agency is involved or what weapons are being . sent, but one said it was not the Pentagon. The CIA has historically . undertaken similar operations. Previously, . the US had insisted on only selling arms to the Iraqi government in . Baghdad, but the Kurdish peshmerga fighters have been losing ground to . Islamic State in recent weeks. However, . they yesterday claimed to have recaptured Gwer and Makhmur, towns near . Irbil, by moving forward rapidly after US air strikes. As . those on the mountain prepared to spend a seventh night in the open . air, an RAF spokesman stressed: ‘The safety of the Yazidi community is . paramount. ‘With a number . of people at the drop sites this morning, the crew made the responsible . decision not to carry out the air drop to ensure that the lives of those . in the area would not be put at risk.’
emergency supplies. A C130 cargo plane had been due to make a second drop of UK aid on the slopes Yazidis and Christians are trapped in appalling the Hercules could not find a clear space to parachute aid bundles down without risking injury are still trapped on Mount Sinjar in northern militants. Another . humanitarian flight will come early today as British and US special .