Footage of Russian warplanes targeting civilians in Syria's second largest city of Aleppo while using white phosphorus munitions emerged over the weekend.

White phosphorus is an incendiary and toxic chemical substance that is banned by the international treaties and its usage constitutes a war crime. The video dated June 8 shows the Russian warplanes targeting Handarat area located just north of Aleppo city center, according to Turkish military sources.

In the footage, white phosphorus is seen dropped by Russian warplanes, while burning in the air and on the ground amid explosions with white smoke.

Two children were reportedly killed and six civilians were injured in the attacks.

The usage of these munitions on civilian areas is a clear violation of United Nations Convention on Certain Conventional Weapons dated 1980 and constitutes a war crime, the sources said.

The smoke of white phosphorus causes sudden scars in lungs and suffocates people to death upon breathing, while causing an inside out burning on human body.

Handarat is located on the corridor that connects opposition-held neighborhoods of Aleppo with the rest rebel-held Syrian territory and the rest of the world. Syrian regime aims to cut off this corridor to lay siege on Aleppo, which is likely to cause a humanitarian catastrophe for hundreds of thousands civilians still residing in opposition-held parts of once Syria's commercial hub.