Su-34 raid on Daraya.
The Russians hit 277 targets in the last 48 hours while flying 48 sorties. The number of targets per sortie gone up.
In contrast the US and its allies hit 11 targets in Syria and 17 in Iraq.
Iran has not yet decided whether or not to join the Vienna talks over Syria.
The Syrian rebels have rejected the Russian plan for a transition.
Turkey has renewed calls for a no fly zone in Syria.