Videos uploaded to social media purport to show the devastating aftermath of Russian air strikes in Deir al-Zor, Aleppo and Damascus on 7 December. The first video appears to show debris and damaged buildings in the eastern Deir al-Zor province. The air strikes are said to have been undertaken by Russian forces.
Syria's ally Russia is waging an air campaign in support of President Bashar al-Assad, and has been striking in Deir al-Zor. Russia's air raids have hit some Islamic State (Isis) targets, but the United States and its allies say most of them have hit other foreign-backed rebel groups.
The second set of videos purport to show a similar scene in Aleppo, where civilians and members of the Syria Civil Defense group are seen helping to pull wounded men from the rubble and carrying them away. The third video appears to show civil defence workers rescuing victims in the Damascus suburb of Douma.
The United States, Britain, France and Russia, amongst others, have all conducted air strikes in the country in response to the threat posed by IS (Daesh) militants, one of the many groups opposed to Assad's rule. The more than four-year-old war shows little sign of slowing across the rest of the country as heavy fighting continues, and all the world's major powers except China are now militarily involved.