A car bomb killed more than 50 people and wounded 200 in central Damascus on Thursday when it blew up on a busy highway close to ruling Baath Party offices and the Russian Embassy, state media and activists said.
Syrian television showed charred and bloodied bodies strewn across the street after the blast, which it described as a suicide bombing by "terrorists" battling President Bashar al-Assad. It said 53 people were killed.
Central Damascus has been relatively insulated from almost two years of unrest and civil war in which around 70,000 people have been killed across the country, but the bloodshed has shattered suburbs around the capital.
Rebels who control districts to the south and east of Damascus have attacked Assad's power base for nearly a month and struck with devastating bombs over the last year.