A British SAS sniper took an Islamic State (Isis) commander's head clean off as he taught jihadi recruits how to behead captives, according to reports. The marksman fired from over a kilometre away (1,000 metres) to land the shot.

The IS (Daesh) fighter was reported to be in the middle of a drill teaching new soldiers how to execute captives, according to the Daily Express. Some 20 new terror recruits were watching as the fatal bullet struck.

The soldier was operating in the northern Syria a fortnight ago and was using a .338 rifle with tumbling ammo that can cause a huge hole in the body on impact. The sniper had assistance from 12 fellow SAS soldiers, who managed to sneak into a jihadi compound before the shot was fired.

One military insider said: "One minute he was standing there and the next his head had exploded. The commander remained standing upright for a couple of seconds before collapsing and that's when panic set in. We later heard most of the recruits deserted. We got rid of 21 terrorists with one bullet."

Following the deadly terror attacks in Paris in November 2015, UK MP's voted to extend British air strikes from Iraq to Syria. British soldiers have been on the ground in Jordan and Turkey, training Syrian rebels fighting Bashar al-Assad, as well as IS.

British soldiers are also preparing to join a multi-national taskforce that will take on IS in Libya. Despite plans to send troops to North Africa, a US-led coalition of nations have to wait until Libya establishes a new parliament that can agree to allow western forces to attack the jihadists near their Sitre stronghold.