A 21-ton airdrop of food that was intended for starving Syrians in the besieged city of Deir el-Zour was damaged, lost or fell into an area covered with land mines, the U.N World Food Programme revealed Thursday.

The delivery, which had been dropped at an altitude of 23,000 feet, would have been enough to feed 2,500 people for a month. But Instead of 10 of the 21 pallets which include foodstuffs such as vegetable oil, lentils, rice and salt landing in the city as planned, they "drifted away and are so far unaccounted for," U.N. World Food Programme spokeswoman Abeer Etefa said, according to NBC News. 

Officials know where the remaining 11 pallets dropped, but they were hardly better off. Four of them landed within the vicinity of the drop zone but became badly damaged because their parachutes didn't open, while the remaining seven are suspected to have landed in no-man's land.

"This plane had to fly at a high altitude to avoid rockets, missiles and gunfire," the spokeswoman added. "We are disappointed that people who were anxiously waiting to receive this food did not receive it."

The results of the operation are a far cry from what was initially reported by the U.N. who cited Syrian Arab Red Crescent teams on the ground who suggested that the first pallet had dropped over the city and landed safely, according to the BBC.

However, the WFP later rectified the report and updated the status of the situation to reflect what we know now through a statement on its website that said the operation "faced technical difficulties and we are debriefing crew and partners in Deir Ezzor to make necessary adjustments."

It continued, explaining that "high altitude drops are extremely challenging to carry out and take more than one trial to develop full accuracy."

Deir el-Zour, a city with a population of about 200,000, lies in Syria's east and is consistently besieged by ISIS - one of the key players in the country's five-year civil war that has claimed at least 250,000 lives. Civilians living in the western side of the city are particularly at risk, and U.N agencies warned last month that its residents were facing "sharply deteriorating conditions."

Wednesday's drop was the first high-altitude air delivery over Syria, but diplomats hope that a ceasefire scheduled to go into effect Saturday will allow aid workers to to deliver food and other services to the country's civilian population rather than rely on road deliveries or air drops which are used as a last resort.