Rescue operation took place in village near Raqqa, Syria earlier this month

A British sniper took out a feared ISIS executioner as he prepared to murder several hostages by shooting a fuel tank on his back and incinerating him.

The SAS marksman fired a single round from his Barrett .50 calibre sniper rifle at the terrorist, who was about to use a flame thrower to kill 12, from 1,500m.

The bullet hit the flame thrower's fuel tank and caused a huge fireball, also killing three other ISIS members who were ready to film the execution.

A British sniper took out a feared ISIS executioner as he prepared to murder several hostages by shooting a fuel tank on his back and incinerating him (stock image)

A source told the Daily Star Sunday how the rescue operation took place in a tiny village near Raqqa, Syria, earlier this month.

Shortly after the explosion, the prisoners - thought to be civilians - were freed by British and US special forces.

The ISIS executioner killed in the mission is said to have been on a US 'kill list' for several months, due to his method of slaughtering prisoners by burning them alive.

The source told the newspaper: “The SAS team moved into an overwatch position above a village where they were told the execution was going to take place.

The SAS marksman fired a single round from his Barrett .50 calibre sniper rifle at the terrorist, who was about to use a flame thrower to kill 12, from 1,500m (stock image)

“Up to 12 civilians were going to be murdered – eight men and four women. They were suspected of being spies.

“The executioner gave some sort of rambling speech over a loud hailer then when he finished the SAS sniper opened fire.'

The rescue comes a few months after another SAS sniper took out two ISIS car bombers with a single shot when they were driving towards their target in Libya.

The heroic sharpshooter saved hundreds of lives by hitting the driver in the head with a deadly shot from 1,000m.

The bullet went through the driver's skull and lodged in the passenger's neck, killing them both.