The strikes took place in the Latakia, Aleppo, Hama and Damascus provinces.

The damage the Russian SU-34 jets caused to the underground bunkers was especially significant, Defense Ministry spokesman Major General Igor Konashenkov said.

They hit the terrorists’ underground infrastructure in Homs, which had allowed the militants to move undetected and increase their effectiveness in combat.

The well-funded Islamic State (IS, formerly ISIS/ISIL) has been hiding whole weapons caches underground, which included explosive devices for carrying out terrorist attacks.

A small missile factory was among the objects destroyed. However, these underground bases and conduits are believed to be widespread across Syria, so more work needs to be done, Konashenkov says.

A frontline supply junction for transporting fuel, arms and food supply lines was also hit in the Damascus province.

The entire command infrastructure of one of the terrorist groups operating in the Hama province was disrupted by the strikes, sending the militants fleeing from the area, the Defense Ministry added.

According to information from the Russian armed forces, desertions on a massive scale are occurring amongst IS ranks in the north and north-east of the country. In the Raqqa province, IS has started a mobilization of everyone aged 14 and over.

In Idlib and Hama, field commanders with Al-Nusra Front are resorting to separating families at gunpoint in order to get their hands on ever younger child soldiers.

Fighting between different jihadist groups over territory control and funds are also on the rise, the Defense Ministry report states. Intercepted radio communications suggest that IS has targeted Al-Nusra Front with three car bombings in the past week.

IS leaders are demanding that their field commanders employ more car bombs and other home-made explosives against advancing Syrian forces, the report says.