The Ministry of Defence has released a video showing the moment an RAF Reaper drone carries out an air strike on Islamic State fighters before they manage to carry out a public execution.
The footage shows two handcuffed prisoners being led from a van and placed in front of a large group of spectators in the Islamic State of Iraq and the Levant-held town of Abu Kamal in eastern Syria.
The drone,manned by servicemen 2,000 miles away at RAF Waddington in Lincolnshire, then releases its single Hellfire missile.
The strike hits an Isil sniper on a nearby roof and the civilians and fighters scatter before the killing can be carried out.
Releasing the footage on Tuesday, the Ministry of Defence explained that it could not target the Isis militants on the ground directly because that would have also killed civilians.
The mission was overseen from a heavily fortified combined air operations centre (Caoc) at the al-Udeid air base in Qatar.
Air Commodore Johnny Stringer, commander of UK air operations in Iraq and Syria, said “The individual whom we engaged was a sniper in over-watch to shoot civilians who sought to move away from the execution, let alone to protect the planned execution itself.
“That particular example for us very much brought it home because civilians had been herded in, forced literally at gunpoint, to go and watch this going on in their hundreds.”
He revealed that the UK had taken out Britons in secret missions to stop specific attacks, adding: “By dint of their activity, by being members of Daesh (Isil) and frankly engaging the people we are here to protect, they (British citizens) become valid military targets and that’s the way we look at it.
“These people know we can find them wherever they try to hide.”
The RAF killed British jihadists in a drone strike in Syria in 2015, the first targeted UK drone attack on its own nationals.
The release came as Sir Michael Fallon, Defence Secretary, announced that drone pilots who bomb Isil fighters could be awarded military medals.
Currently medals are awarded according to a consideration of rigour and risk, with risk defined as being physically exposed to danger.
But Sir Michael Fallon said a rethink may be needed as the UK deploys more unmanned aircraft on operations such as those targeting Isil, otherwise known as Daesh, from the skies above Iraq and Syria as part of Operation Shader.
Speaking on a visit to British troops in Iraq, he said: “The changing character of warfare provides new challenges – not just about how we fight but also how we recognise and support those who serve.
“As fighting has evolved we have adapted, ensuring our troops have cutting-edge equipment including unmanned systems operated from outside the battlespace. Our recognition of service, the risks taken, and the long-term effects must therefore adapt too.
“That is why we need to examine how to provide medallic recognition for those making a vital contribution to Op Shader outside the battlespace, from Reaper pilots taking life-and-death decisions to those who ensure our planes can strike Daesh targets.”
Sir Michael also announced the creation of an Operation Shader medal for those who have fought Isil, which he described as “the evil of our time”.
The Defence Secretary said: “It is only right that those who’ve performed above and beyond in this fight against the evil of our time get the recognition they deserve. This medal will do just that.
“Our troops have made huge contributions to the fight against Daesh, helping end its tyranny in large parts of Iraq and Syria.
“They have conducted over 1,500 strikes against Daesh terrorist targets and helped train nearly 60,000 Iraqi Security Forces.
“The campaign is not over but for those that have served we rightly honour the critical role they have played in helping keep us safe.”
Britain has provided more than 1,400 servicemen and women to the global coalition fighting Isil and there are currently around 600 soldiers on the ground in Iraq, mainly training local security forces.