WARNING--EDIT CONTAINS GRAPHIC IMAGES
Syrians race through the streets of al Bab where sources say dozens are dead in air raids.
At the scene, smoke billows from the ruins as a frantic search for survivors is underway.
Locals say helicopters and war planes dropped barrel bombs on residential and industrial areas of the Islamic State-controlled city, which sits northeast of Aleppo.
The Syrian Observatory for Human Rights says this raid killed 37 people.
Reuters cannot independently verify the video, which was posted on a social media website.
Across the country, the monitoring group reports more than 470 government strikes had killed at least 110 civilians in the last 72 hours... another deadly sign of a war without an end in sight.