Global attention turned to Madaya, Syria earlier this month when images of emaciated residents, including many children, emerged from the besieged Syrian city and caused so much international outcry the Syrian government was forced to let food and medicine through, the Huffington Post reports.

Yet while Madaya made headlines, hundreds of thousands of Syrians elsewhere in the country are deprived of regular access to aid. There are 4.5 million people within Syria in regions that are hard to reach for aid groups, 400,000 of whom live in besieged areas, according to the United Nations.

Human rights groups and activists contend that the Assad regime has used food as a weapon of war since the beginning of the conflict. Through denial of aid shipments and siege tactics, government forces have levied a kind of collective punishment on areas under opposition control.

Only 10 percent of requests to send aid convoys to these 4.5 million people are granted, the UN says. The United Nations agencies require a degree of coordination with armed groups and government forces in order to deliver aid, even though access to humanitarian relief is held as a right under international law.

Syrians under siege often go without supplies for extremely long stretches of time. They are forced to ration out what they do have and rely on extremely expensive black market goods, or, in dire situations, turn to eating things like grass or leaves.