Reuters is reporting at least 53 dead and more than 200 wounded in a car bomb blast outside of Baath party headquarters in Damascus.
Meanwhile, the government bombed a civilian neighborhood in the capital killing 18 more:
A car bomb killed 53 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, Syrian television said.
TV footage showed charred and bloodied bodies strewn across the street after the blast, which state media said was the result of a suicide bombing by "terrorists" battling President Bashar al-Assad.
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.
The al Qaeda-linked rebel group Jabhat al-Nusra, which claimed responsibility for several of those bombs, says it carried out 17 attacks around Damascus in the first half of February, including at least seven bombings.
Activists said most of the victims of Thursday's attack in the city's Mazraa district were civilians, including children, possibly from a school behind the Baath building.
Opposition activists reported further explosions elsewhere in the city after the explosion which struck shortly before 11 a.m. (0900 GMT).
One resident in the heart of the capital heard three or four projectiles whistling through the sky, followed by explosions. At least one of them landed in a public garden in the Abu Rummaneh district, she said, but no one was hurt.
The bloody stalemate continues while the opposition agreed to talks with the government - but not before President Assad had stepped down.