UN human rights chief Zeid Ra'ad al-Hussein said on Friday that the humanitarian situation in the besieged Eastern Ghouta area outside the Syrian capital is "an outrage" and parties to the conflict must allow food and medicine to reach at least 350,000 trapped Syrians.
“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,” Zeid said in a statement.
He added: “I remind all parties that the deliberate starvation of civilians 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.”
A deal reached between rebel backer Turkey and regime allies Russia and Iran earlier this year has created so-called "de-escalation zones" in several parts of the country, including rebel-held Eastern Ghouta, bringing a measure of calm.
One of the aims was to facilitate aid access to besieged areas. But the tightening siege in Eastern Ghouta has pushed people to the verge of famine in the rebel enclave, residents and aid workers have told Reuters.
A UN convoy last reached the besieged area on Sept 23, with aid for 25,000 people.
The UN's children's fund UNICEF told AFP on Monday that more than 1,100 children are suffering from acute malnutrition in the area.
Activists say two children have died of starvation in the last two months.
On Thursday, Syrian regime shelling on the area killed at least eight civilians, the Syrian Observatory for Human Rights said.
An AFP correspondent in Douma saw wounded civilians being treated at a makeshift clinic where distressed families were mourning the dead.
The Britain-based Observatory reported "six civilians, including a child, killed by artillery fire in Douma and two others by a shell fired by regime forces in (nearby) Saqba".