Many of the planes over the suburb near Damascus appear to be Russian – part of the military force sent by Russia’s President Vladimir Putin to prop up Syrian president Bashar Assad, the organisation added.
Yesterday one besieged resident Bilal Abu Salah, 22, whose wife is five months pregnant with their first child, said: “We are waiting our turn to die. This is the only thing I can say.
“Nearly all people living here live in shelters now. There are five or six families in one home. There is no food, no markets.”
UN secretary general Antonio Guterres said the Syrian government’s bombing campaign had turned the region into “hell on earth” for civilians.
The UN’s human rights chief Zeid Ra’ad Al Hussein condemned a “monstrous campaign of annihilation”.
He described the horrifying situation where “civilians are slaughtered in droves in order to fulfil political or military objectives”.
The International Committee of the Red Cross called for humanitarian access and warned of worse to come.
Its head of delegation in Syria, Marianne Gasser, said: “The fighting appears likely to cause much more suffering in the days and weeks ahead. This is madness and it has to stop.”
The Union of Medical Care and Relief Organisations accused Assad’s Russian-backed forces of unleashing 127 air strikes in 48 hours plus “countless mortar and artillery strikes” as well as illegal barrel bombs dropped from helicopters.
Its chairman, Birmingham GP Dr Ghanem Tayara, said: “There are unknown numbers of civilians trapped under the rubble of demolished buildings. Thousands of civilians, mostly women and children, have sought shelter in poorly equipped underground shelters with little or no clean water or food stocks.
“The streets of Ghouta are apocalyptic. It takes great cowardice to attack schools, hospitals and civilians.
“To intentional and systematically gas, burn, bomb and starve your own civilians with foreign assistance.”