The Ministry of Defence has admitted that an RAF airstrike has resulted in the death of a civilian - the first innocent casualty since it started bombing the Islamic State (IS) group in Iraq and Syria.
Defence officials say an attack on a vehicle in Eastern Syria involving a drone unintentionally killed a person on a motorbike who entered the target area at the last moment.
Analysis of evidence concluded that the motorcyclist was not a member of IS.
In a statement Defence Secretary Gavin Williamson said:
"We do everything we can to minimise the risk to civilian life from UK strikes through our rigorous targeting processes and the professionalism of UK Service personnel.
"It is therefore deeply regrettable that a UK air strike on 26 March 2018, targeting Daesh fighters in eastern Syria, resulted in an unintentional civilian fatality.
"During a strike to engage three Daesh fighters, a civilian motorbike crossed into the strike area at the last moment and it is assessed that one civilian was unintentionally killed.
"We reached this conclusion after undertaking routine and detailed post-strike analysis of all available evidence."
The revelation follows accusations in a BBC report that RAF airstrikes in Iraq may have killed civilians.
According to the BBC, the source has cast doubt on the MoD’s long-maintained statement it has seen “no evidence” that its strikes against so-called Islamic State (IS) in Iraq have caused civilian casualties.
The coalition insider, who has not been named, told the BBC the MoD’s statement is “nonsense” and that RAF strikes have caused civilian casualties on several occasions.
He said: “It’s impossible to conduct a bombing campaign in highly populated areas without killing civilians.
“I’m certain from what I’ve seen and what I know that British airstrikes have caused civilian casualties on several occasions."
“To suggest they have not, as has been done, is nonsense.”
Over four years, the RAF has dropped or fired more than 3,500 bombs and missiles against IS in Iraq and Syria.
The coalition reportedly dropped nearly 30,000 munitions during the battle to clear Islamic State from Mosul.
RAF jets based in Cyprus played a key part in the battle, reportedly hitting 750 IS targets.
The source quoted by the BBC said during one strike on what the MoD says was a lorry bomb, two civilians were killed in a huge secondary explosion.
The MoD has refused to release footage of the strike but has told the BBC the strike was subject to “very careful analysis” and those killed were “highly probably” IS fighters.
The BBC investigation also found evidence that some RAF weapons had malfunctioned or failed to detonate, while others had strayed off target and hit buildings that weren’t under surveillance.
The MoD has always pointed to the professionalism of the RAF’s aircrew and their use of precision weapons.
But – as the report points out – saying “no evidence” RAF airstrikes have hurt non-combatants, doesn’t rule out the possibility it has happened.
The US-led coalition has admitted unintentionally causing 831 civilian deaths during four years of operations against IS.