Slain Iranian general Qassim Solemaini’s militias are secretly fighting in Syria’s final rebel stronghold, radio communications leaked to the Telegraph show.

The rare recordings reveal how Iranian soldiers and Afghan mercenaries are directing military operations in Idlib, northwest Syria, in a battle they had promised not to take part in during peace talks.

Soleimani’s powerful, shadowy Quds Force has been instrumental in helping swing the war in President Bashar al-Assad’s favour. However, Tehran is understood to have made assurances to Turkey, which backs the opposition in Syria, not to send troops to Idlib due to the proximity of the province to Ankara’s border.

The commander of the Fatemiyoun Division, an Afghan Shia militia fighting under the Quds Force umbrella, last week said that prior to his death Soleimani had given instructions for the paramilitary group's strategy for the next five years, and that his assassination would not cause any “disruptions”.

The claim suggests that the militias in Idlib are there on Soleimani’s command and acting out his plans.