The majority of strikes, according to the analysis, have instead been in areas held by other groups opposed to Syrian President Bashar al-Assad, which include al Qaeda offshoots but also fighters backed by Washington and its allies.

Defence ministry statements of targets hit by the Russian Air Force and an online archive of Russian military maps show Russia has hit 64 named locations since President Vladimir Putin ordered the first round of air strikes three weeks ago.

Of those targets, a maximum of 15 were in areas held by Islamic State, according to a survey of locations of the rival forces in Syria compiled by the Institute for the Study of War.

“If you look at the map, you can easily understand that they are not fighting Islamic State but other opposition groups,” said Alexander Golts, a Moscow-based defense columnist and deputy editor of online newspaper Yezhednevny Zhurnal.