The UN claimed to have successfully air dropped food and medical supplies in the besieged Syrian city of Deir al-Zour on Wednesday. Stephen O’Brien, head the UN’s World Food Program, told the Security Council that the plane dropped 21 tonnes of humanitarian aid on a government-held part of the city.

“Earlier this morning, a WFP plane dropped the first cargo of 21 tons of items into Deir el-Zour,” DW quoted O’Brien as telling the Council. He admitted that air dropping of aid is the least effective approach by cited its benefits as the last resort.

Arab Red Crescent teams on the ground confirmed that pallets reached the targets successfully.

According to a recent UN report, civilians who are trapped in the besieged areas suffer from severe malnutrition and have died of starvation. According to UN, about 200,000 civilians are trapped in the city of Deir al-Zour, the BBC reported.

The city lying on the banks of Euphrates River in eastern Syria had a pre-war population of 240,000 and was besieged by the ISIS which made aid delivery by ground impossible. The last aid was air dropped by Russia in January as a part of a support campaign towards Syrian President Bashar al-Assad.

Last week, around 80,000 people in five other besieged areas of Syria received food and other supplies that were delivered to them by 100 lorries.

The UK government said that air drops bear high risks and should only be considered as the last resort. According to Jan Egeland, who chairs a humanitarian task force, it was the last way left to feed the people trapped in the area, as access to the cities by roads were blocked by the groups engaged in war.

According to the UN estimates, around 480,000 people are living in the besieged areas of the country, with another 4 million in areas that are hard to reach.