Rebel sources in Syria say forces loyal to President Bashar al-Assad killed at least 85 people, including women and children, after storming a Damascus suburb following five days of intense fighting.
Graphic videos uploaded onto a social networking site purported to show the bodies of people who had been executed.
Further amateur videos purporting to come from Homs, showed rebel soldiers fighting and being treated in a makeshift hospital.
It came on the day when US Secretary of State John Kerry announced the States would be more than doubling its non lethal aid to opposition forces to 250,000 dollars (190,000 euros) but stopped short of offering weapons.
Meanwhile as the international community looks for unity among the Syrian opposition the leader of the National Coalition, Ahmed Moaz al-Khatib, refiled his resignation a month after he first said he was stepping down.
This leaves the group searching for a new leader two weeks before National Coalition elections are due to take place.
Khatib has been a vocal critic of the International community’s lack of action in toppling Assad.