This amateur video from Syria purports to capture the moments after a suicide car bomb blast. It reportedly happened at a checkpoint on the outskirts of the capital, Damascus, on Saturday. Reuters can't verify the video. But a monitoring group says a suicide bomber from the al Qaeda-linked Nusra Front was responsible. The bomb blast was followed by clashes with rebels, says the pro-opposition Syrian Observatory for Human Rights, killing at least 16 members of Syria's security forces.