Bombardment of the enclave on the outskirts of Damascus on Tuesday killed 106 civilians, including 19 children, the Observatory said. Since then, activists say more than 60 children have died and at least 1,400 people have been injured, and another hospital has been put out of service.
About 400,000 people reportedly live there.
They're responsible for the attacks, for the dire humanitarian situation in East Ghouta and for the horrendous civilian death toll.
Such tactics appear to flout global law but Russia, Syria's ally, has vetoed 11 U.N. Security Council resolutions criticising its handling of the war.
The US position on the humanitarian situation in Eastern Ghouta, a militant-controlled suburb of the Syrian capital Damascus, is a clear example of "double standards", the Russian deputy foreign minister has said.
"There are attempts from some global and local sides for a truce process in eastern Ghouta and they have not succeeded so far", said Mohammad Alloush, the political chief of Jaish al-Islam, one of the main rebel factions in eastern Ghouta.More news: Primary election early voting opens tomorrow
"Without the support of these two allies, Assad's regime would not be where it is today, and undoubtedly, without this support, this regime would have to show more readiness to negotiate in the United Nations (peace) process", the German government spokesman added.
What is happening now in Eastern Ghouta in particular, and Syria in general, is ethnic cleansing. "But people think we are numbers". His statement comes amid concerns about escalating violence between Syrian government forces and rebel, as well as Islamist, factions operating in the area.
"What is happening in Damascus and Eastern Ghouta is complete madness", said Sedky.
Ahmad al-Dbis, an official at the Union of Medical Care and Relief Organizations, which runs hospitals and clinics in Syrian opposition areas, says ten hospitals have been damaged by airstrikes or shelling in the last 48 hours. He added that the nightmare in East Ghouta has to end and must end now.
It demands the immediate lifting of all sieges including in Eastern Ghouta, Yarmouk, Foua and Kefraya and orders all sides to "cease depriving civilians of food and medicine indispensable to their survival".