LONDON — Former Islamic State hostages and families of the group’s victims are urging Britain and the United States to put two recently captured extremists on trial, arguing that denying them justice will fuel the hatred and violence they supported.
French journalist Nicolas Henin, who was held by the men and their comrades for 10 months, said he wants justice after the arrest of the two Britons, who were part of the notorious cell dubbed ‘‘The Beatles.’’
Henin said the men should be tried in the United Kingdom, not shipped to the military detention center at Guantanamo Bay, because revenge will just breed more violence.
‘‘What I’m looking for is justice and Guantanamo is a denial of justice,’’ he said Friday. ‘‘There hasn’t been a single trial in 16 years there. . . . Guantanamo was actually one of the reasons for their engagement in extremism, in jihad. So if we perpetrate this kind of atrocity, we are not helping our quest for justice.’’
US officials have confirmed that El Shafee Elsheikh, 29, and Alexanda Amon Kotey, 34, who grew up in London before traveling to the Middle East to join the Islamic State, were captured in early January in eastern Syria.
US officials have interrogated the men, who were allegedly part of the ISIS cell that captured, tortured, and beheaded more than two dozen hostages, including American journalists James Foley and Steven Sotloff, and American aid worker Peter Kassig.
Foley, a former New Hampshire resident, was a free-lance correspondent for the Boston-based website GlobalPost. His mother, Diane Foley, said the crimes of Elsheikh and Kotey crimes are ‘‘beyond imagination’’ and they should spend the rest of their lives in prison.
‘‘I’d like them to be brought to trial in the United States, but as long as they’re brought to fair trial and detained and justice is served, I would be most grateful,’’ she told the BBC.
The Justice Department has not said whether it plans to prosecute the two men or turn them over to the US military detention center at Guantanamo Bay.
Britain, a close ally of the United States, could object to sending the men to the wartime prison, which is viewed with disfavor abroad because of interrogation techniques and because many prisoners there have not been brought to trial.
Hundreds of foreign citizens fought alongside ISIS as it took control of large parts of Syria, raising concerns that they will bring terrorism with them if they ever return home.
The capture of Elsheikh and Kotey could yield precious intelligence about what happened to those fighters as ISIS was defeated on the battlefield, and information about the fate of their hostages, said Shiraz Maher, a senior research fellow at the International Center for the Study of Radicalization and Political Violence at King’s College London.
‘‘It’s hugely significant for a lot of the Western countries who had hostages who were captured by Islamic State,’’ he said. ‘‘I think it demonstrates that there remain high-value, significant players at large.’’
Maher agreed that Elsheikh and Kotey should be brought to trial because it will help bring closure to their victims and send a message to anyone who considers joining ISIS or other extremist groups.
‘‘These guys had an absolute sense of their own invincibility,’’ he said. ‘‘They were filled with euphoria. [Trials] will make people think twice.’’
The two are believed to be linked to Mohammed Emwazi, the masked British insurgent known as Jihadi John who appeared in several videos that showed the beheading of Western hostages. The cell was nicknamed ‘‘The Beatles’’ because all four members had English accents.
The American-backed Syrian Democratic Forces captured the two men last month, and the United States helped identify them with biometric data and other tools. Their capture was first reported by The New York Times.
The United States has been training the SDF in border and internal security, including how to screen individuals and determine if they are foreign fighters or other enemies hiding in the general population.
Elsheikh, a former child refugee, was a mechanic from White City in west London. Kotey is from London’s Paddington neighborhood. Kotey’s family issued a statement saying they were aware of the arrest and asking that their privacy be respected.
The US State Department last year imposed sanctions on the two men after declaring they were terrorists.
Elsheikh traveled to Syria in 2012, initially joining Al Qaeda’s branch in the country before moving on to ISIS, the State Department said. Kotey served as a guard for the execution cell.
Elsheikh, it said, ‘‘earned a reputation for waterboarding, mock executions, and crucifixions while serving as an [ISIS] jailer.’’
‘‘As a guard for the cell, Kotey likely engaged in the group’s executions and exceptionally cruel torture methods, including electronic shock and waterboarding,’’ the State Department said.
Emwazi died in a US airstrike in 2015. The fourth member of the cell, Aine Lesley Davis, was convicted of being a member of a terrorist organization and jailed for 7½ years by a court in Turkey in May 2017.