At least 25 people have been killed in the Yarmouk refugee camp in southern Damascus. Syrian fighter-bombers fired at least one missile into a mosque in the camp that was sheltering 600 people from the intense fighting in surrounding areas.
It is the first time the camp, home to nearly half a million Palestinians, many of whom are supporting Bashar al-Assad, has been attacked from the air. But Yarmouk is also the scene of fighting between pro and anti-Assad Palestinian forces, the latter fighting alongside the rebels.
Yarmouk sits in the swathe of territory in southern Damascus that is under rebel control, or where rebels are squeezing government forces who are often assisted by fighters from the Popular Front for the Liberation of Palestine. Their military leader left the city along with his son just hours before the airstrike.
It is an unexpected consequence of the conflict; with many Palestinians fighting with the rebels their movement is split, a problem Hamas avoided when it quietly pulled out of Syria when the fighting started.