An air strike on a rebel-held town southwest of the Syrian capital Damascus has left 20 people dead, according to opposition activists. Latest unverifiable video appears to show the scale of destruction around the city. It comes a day after activists claim forces loyal to President Bashar al-Assad killed at least 36 people, 14 of them children, in bombardments of rebel-held eastern areas near the capital. Some sources say this air, rocket and artillery campaign is the heaviest since rebels overran a helicopter base and missile base near Damascus two months ago and encroached on the main international airport. Meanwhile, aid agencies are warning that Syria’s civil war is unleashing what they call a “staggering humanitarian disaster”. Many of the hundreds of thousands of refugees who have fled the fighting have cited fear of rape as their main reason for leaving the country, claiming that gang rapes often occur in front of family members.