Mangled metal, puffs of smoke, chunks of concrete, blood and a crowd of people walking around dazed, shocked and crying. That was the scene on a Damascus street Friday after a car bomb exploded and killed several people. Some of the dead were reported to be children.

The blast seemed to mock the truce that the Syrian government and rebels agreed to abide by earlier this week. The truce, negotiated by the United Nations' special envoy to Syria, was supposed to last during Eid al-Adha, the four-day Muslim holiday that celebrates the end of the Hajj. A Syrian purportedly at the scene captured a video and posted it on YouTube.

CNN cannot verify that the footage is authentic, just like so many amateur videos shot during a war that foreign journalists have been blocked from covering.

Rebels said the blast went off near a playground.

This kind of violence isn't normal in a neighborhood such as Zouhr, a government-held stronghold. Zouhr has been generally quiet; there are still pockets in the capital city that have avoided chaos.

That explains why parents might believe that they could safely bring their kids to a playground to celebrate Eid. There's a mosque nearby, and it's customary to gather with family and pray to mark the holiday.

About 15 minutes after the blast, Syria security forces showed up and shot directly at someone filming the scene, a source who CNN has spoken with before inside Syria recounted. CNN is not naming her to protect her safety.

"The people were mad with grief, with rage," she said.

A small demonstration formed, as Syrians chanted against the Assad regime, she said.

They immediately blamed President Bashar al-Assad's forces for the bomb.