The two British Isis members accused of involvement in the beheading of western hostages are being taken to Iraq by the United States military as the Turkish offensive in north-east Syria gets into its second day.
Both CNN and the Washington Post also reported the US military had taken custody of the two fighters, while ABC said they had been transferred to a safe location.
Turkey is attacking the USA -backed Syrian Defense Forces, a Kurdish force that battled the Islamic State group alongside American troops and now is responsible for guarding thousands of detained militants.
President Trump announced on Monday that US troops would withdraw from northeast Syria, in advance of a planned invasion of the area by Turkey. "We have a certain number of ISIS fighters that are particularly bad, and we wanted to make sure that nothing happened with them in respect to getting out".
"We are taking some of the most risky ISIS fighters out and we're putting them in different locations where it's secure", Trump said at the White House.
The accused, El Shafee Elsheikh and Alexanda Kotey, are suspected of operating a four-man Islamic State cell in Syria that sought to abduct and kill Westerners.
In March, Kurdish and USA forces cleared the last members of the Islamic State group from what was left of their self-declared caliphate, which once sprawled across a large part of Iraq and Syria.
Other members of the "Beatles" terror cell included Aine Davis, who has been jailed in Turkey, and Mohammed Emwazi - otherwise known as Jihadi John, who appeared in several videos executing hostages.
The SDF-held fighters include around 2,000 of foreign nationality, many of them from European countries that have refused to take them back.
The Kurds - who helped defeat IS in Syria and were key in their fight against fighters and their relative in prisons and camps in areas under their control.
The Kurds also hold thousands of ISIS fighters in detention centers. It is not clear how many prisoners are involved in the transfer. They were also unapologetic, denouncing the US and Britain as "hypocrites" who will not give them a fair trial.
The pair, who were raised in the United Kingdom but have since been stripped of their British citizenship, are among thousands of IS fighters, including others from Britain, who have been held in camps in the region.
That decision had been challenged by Elsheikh's mother, who took her case to the supreme court in London, to prevent the two men being extradited to the USA and instead put on trial in their home country.
Overnight Trump said that he had spoken to the British prime minister, Boris Johnson, on the subject of Isis prisoners, but did not say whether he was referring to Kotey and Elsheikh.