The UN on Friday hit out at the deliberate starvation of at least 350,000 besieged civilians in Eastern Ghouta, Syria, describing it as an "outrage".
It said such as a method of warfare "constitutes a clear violation of international humanitarian law, and may amount to a crime against humanity and/or a war crime".
UN High Commissioner for Human Rights Zeid Ra'ad al-Hussein said in a statement: "I also call on all those with involvement or influence in the conflict to facilitate the access of humanitarian workers so they can deliver the aid that the people of Eastern Ghouta so desperately need."
Hussein called on the parties to the conflict to allow "badly needed" food and medical supplies to get into the area.
"The shocking images of what appear to be severely malnourished children that have emerged in recent days are a frightening indication of the plight of people in Eastern Ghouta, who are now facing a humanitarian emergency," the high commissioner said.
A main opposition stronghold on the outskirts of Damascus, Eastern Ghouta has been under siege by Bashar al-Assad regime forces since December 2012.
"Residential areas, including those areas previously spared attack, are now being hit on an almost daily basis by ground-based strikes by government forces and their allies, with reports speaking of scores of civilian casualties," Hussein said.
Noting that the UN last reached Eastern Ghouta on Sept. 23, he said the Syrian regime only accepted 26 percent of requests to deliver assistance between January and September this year.
"The [Syrian] government has also reportedly imposed severe restrictions on medical evacuations, which is said to have resulted in the death of several civilians," he said.
Hunger has killed at least 397 civilians in Eastern Ghouta. In a statement on Tuesday, the Syrian Network for Human Rights (SNHR) said the fatalities included 206 children and 67 women.
Last week, two Syrian babies died from malnutrition caused by the regime blockade.
The NGO said regime forces had launched a military operation in eastern Damascus in February and shut underground tunnels used to smuggle foodstuffs to civilians in Eastern Ghouta.
