A drone strike by the Royal Air Force which halted the execution of prisoners by Islamic State also wounded up to 20 civilians, according to a local monitoring group.
The Ministry of Defence (MoD) claimed on Monday (May 15) the RAF reaper strike on Abu Kamal in eastern Syria had disrupted an execution ceremony by Isis militants six days earlier.
The RAF had been monitoring the situation through the drone, and when it became clear there was to be a public execution, they launched a missle from the craft - killing sentries stationed above the crowd and causing the Isis fighters to flee.
But the Syrian Observatory of Human Rights claims "up to 20 other people, mostly civilians" were also injured by the strike.
However it must be stressed that the SOHR is only a single source, and there is at present no verification of its claim.