Britain's defence ministry announced on Thursday it had established an independent inquiry to investigate allegations of unlawful killings by British soldiers in Afghanistan over a decade ago.

Commandos in the elite Special Air Service (SAS) corps have been accused of killing dozens of Afghans in suspicious circumstances, but the military chain of command concealed concerns, the BBC claimed earlier this year.

Unarmed Afghan men were routinely shot dead "in cold blood" by SAS troops during night-time raids, and weapons were planted on them to justify the crimes, the broadcaster reported following its own four-year probe.

The newly launched statutory inquiry -- to start early next year and be chaired by senior judge Charles Haddon-Cave -- will probe the alleged wrongdoing spanning a period from mid-2010 to mid-2013.

It will also scrutinise the "adequacy" of the Ministry of Defence's response to the concerns raised about soldiers' conduct and "assess what lessons can be learned", the ministry said.

"If there are further lessons to learn it is right that we consider those fully to ensure all allegations are handled appropriately and in equal measure," Defence Secretary Ben Wallace said in a statement.

He added that would "ensure our personnel are adequately protected from unnecessary reinvestigations".

Wallace said the MoD had made "a number of changes" in recent years to deal with serious allegations of wrongdoing, including the creation of a Defence Serious Crime Unit.

The BBC's Panorama programme investigation identified 54 people shot dead in suspicious circumstances by one SAS unit during a six-month tour of Helmand province in southern Afghanistan from November 2010 to May 2011.

Senior officers including General Mark Carleton-Smith, who headed UK Special Forces at the time, were aware of concerns within the SAS about the operations but failed to report them to military police, it said.

Under UK law governing the armed forces, it is a criminal offence for a commanding officer to fail to inform the military police if they become aware of potential war crimes, the BBC noted.

The MoD has said previous investigations into the conduct of UK forces in Afghanistan had found insufficient evidence to bring charges.

The families of eight people, including three young boys, who allege they were murdered by British soldiers in two separate night raids in Afghanistan in 2011 and 2012, welcomed the announcement.

"My family has waited 10 years to find out why this happened," a member of the Noorzai family said in a statement released via their London-based law firm.

"We are happy that finally after so many years someone is going to investigate this thoroughly.

"We live in hope that those responsible will one day be held to account."