LONDON: The daughter of a British hostage murdered by the notorious Islamic State group kidnapping cell nicknamed "The Beatles" called Friday for the last two members, now captured, to face justice.
Alexanda Amon Kotey and El Shafee el-Sheikh, both from Britain, were captured in January in eastern Syria by the US-backed Syrian Democratic Forces.
The IS jihadist group cell was behind a series of videotaped beheadings.
Bethany Haines, whose aid worker father David was killed in 2014 after being held captive for 18 months, said she hoped the pair's detention could bring some closure to bereaved families.
"The first thought was relief, finally to know that the people that were involved in my dad's murder have been caught and will sort of serve some justice," she told ITV television.
She said she wanted them to be "locked up with the key thrown away".
Britain's Defence Secretary Gavin Williamson told The Times newspaper: "These are people who have done absolutely vile and despicable crimes and brought absolutely so much misery.
"It is good that they have been hunted down and caught."
French journalist Nicolas Henin, who was held captive by Islamic State for 10 months, demanded the men be brought to justice.
"This is the beginning of a process that will bring them eventually, hopefully, to a trial," he told Sky News.
"Guantanamo is a denial of justice. What I want is a trial and a trial potentially that I can attend, so rather, a trial in London rather than one in Kobani in northern Syria."
The Daily Telegraph newspaper said it understood that Britain would not hinder any moves to extradite the pair to the United States.
Sources told the broadsheet that there was little desire among ministers to repatriate them to Britain.
Shiraz Maher, Deputy Director of the International Centre for the Study of Radicalisation at King's College London, said that IS losing territory did not mean they were no longer a threat.
"The capture of these men is hugely significant because very few high profile IS targets have actually been caught," he said.
"These men will have important intelligence about the fates of Western hostages in their custody, including some who remain captives of Islamic State.
"European foreign fighters very much remain a part of this organisation and continue to play a role in the next phase of its mutation as it reverts back to its insurgent roots."