The latest raids came after at least seven civilians, including five children, were killed Tuesday by air strikes in northwestern Idlib province, the last outside government control, the Observatory said.
Russian Federation has given President Bashar al-Assad's government crucial support throughout Syria's civil war, which has killed hundreds of thousands of people and driven millions from their homes since it began with a crackdown on pro-democracy protests in 2011.
If confirmed, it would be the single biggest loss of military hardware for the Kremlin strongman since he began supporting Syria's president Bashar al-Assad.
Since then, hundreds of thousands of people have been killed and more than 10 million others displaced, according to United Nations officials.
Eastern Ghouta, a small enclave east of the capital Damascus, is controlled mostly by rebels from the Jaish al-Islam group.
The Observatory, a war monitor based in Britain, said 11 women and a child were among the dead in the strikes in Misraba, which it said were carried out by Russian planes.
The United Nations has made repeated calls for warring parties to abide by their responsibility to protect children in line with global humanitarian and human rights law.
Assad forces have been bombing Eastern Ghouta since November 14.
The Defense Ministry on Thursday said two Russian military personnel were killed during a mortar attack on the Khmeimim Air Base in Syria's Latakia province on December 31, 2017.
The Ministry of Defense pointed out that on December 31, at sunset, the military installation in Latakia province was attacked by a mobile group of fundamentalists, but the operational capacity of its air units was not affected at all.
"At least four Su-24 bombers, two Su-35S fighters, an An-72 military transport aircraft and an ammunition depot were destroyed at the Russian Khmeimim airbase on the same day a Russian Mi-24 helicopter was destroyed", Turchynov said.