A US-led coalition’s helicopter, for the second time this week, transferred members of ISIS terrorist group in Syria’s eastern Dayr al-Zawr Province, said a UK-based rights group.

According to the Syrian Observatory for Human Rights (SOHR), the airlift was conducted in the town of al-Tabani, on the western outskirts of Dayr al-Zawr, on Saturday.

The operation was accompanied by support from the US-backed Syrian Democratic Forces (SDF), Syrian sources said.

They also said that the operation was possibly meant to transfer US mercenaries fighting alongside ISIS or the terror group’s ringleaders who sought to flee.

Washington has on numerous occasions been accused of colluding with ISIS insurgents to provide safe passage and logistic support to the members of the terrorist group in conflict zones.

The US-led coalition has been targeting what they call ISIS positions inside Syria since September 2014 without any authorization from the Syrian government or a UN mandate.

The airstrikes have many times resulted in civilian casualties.

In another incident on Thursday, the US helicopters took four ISIS members and a civilian from a house used as an arms depot in Beqres, a suburban area east of Dayr al-Zawr, the SOHR reported.

The transferred terrorists included a foreign bomb expert, three Egyptian Daesh members and a civilian.