Hastily-shot footage shows Palestinian refugees streaming out of the Yarmouk refugee camp in Damascus.
Opposition activists say inside it is a battleground as pro- and anti-government factions fight it out.
Government jets are said to have bombed the area on Sunday.
An estimated 2,000 people have crossed the border into Lebanon, putting resources further pressure on resources.
Turkey’s foreign minister has become the latest high profile official to call for the fighting to stop.
Speaking in Ankara, Ahmet Davutoglu called on Iran to use its influence with Damascus to bring an end to the conflict.
Germany, meanwhile, has got its Patriot missiles out of the cupboard in preparation for deployment to Turkey. Two batteries and 400 soldiers are being sent as part of NATO’s committment to help Turkey defend its border.