At least 40 people have been killed in a missile attack on the Syrian capital Damascus.
It is reported 11 missiles targeted the rebel-held suburb of Douma, some of them hitting a market.
Anti-government observers have said the attack was carried out by the forces of President Assad.
The fatalities come as a summit of world leaders takes place in Vienna to discuss possible peace talks.
Until now Iran has not been involved in discussions about how to resolve the civil war, but has today joined the US, Russia, Saudi Arabia and Turkey for the discussion.
The UK's Foreign Secretary Philip Hammond is also attending the talks and is hopeful of finding a way forward.
“This is an exploratory discussion we want to see if there is a way forward, if there is a way of establishing a process, which can end the suffering and the killing in Syria.”