The FBI has announced charges against two suspected British terrorists accused of being part of a "notoriously brutal" Islamic State cell known as "The Beatles".
Alexanda Kotey and El Shafee Elsheikh, both in their 30s and from west London, allegedly belonged to the cell of executioners in Syria - known as "The Beatles" because of their British accents.
FBI director Christopher Wray said: "The defendants are charged with terrorism offences related to hostage taking and killing of four Americans, as well as citizens of Great Britain and Japan.
"I am pleased to confirm they are now in FBI custody, and will soon appear in federal court in the eastern district of Virginia. Today is a good day, but it is also a solemn one."
Kotey and Elsheikh are said to be responsible for the deaths of a number of Western captives, including Britons Alan Henning and David Haines.
Islamic State is a militant group known for beheadings and the barbaric treatment of aid workers, journalists and other hostages in Syria.
Many of these executions were filmed and broadcast around the world in graphic detail.
The pair were captured by the Syrian Democratic Forces in January 2018 and transferred to the custody of the US military in Iraq in October 2019, remaining there ever since.
Last month, families of the men allegedly killed by the pair welcomed news they were likely to face trial in the US after a High Court ruling allowed the UK to hand over case information.
After the ruling, Home Secretary Priti Patel announced that "further evidence to support the prosecution" of the two men was "finally" sent to the US.
Mr Haines, a 44-year-old former aircraft engineer and humanitarian from Perth in Scotland, was beheaded in Syria in 2014 after being held prisoner for 18 months.
Mr Henning, a 47-year-old aid worker from Lancashire, was also beheaded in 2014 after being captured by extremists in Syria.
Their deaths, and several others, were filmed and used for propaganda by extremists.
The cell's ringleader was said to have been Mohammed Emwazi, known as Jihadi John, who was killed in a US airstrike in 2015.
The group's fourth member, Aine Davis, was later jailed in Turkey.