An HIS Conflict Monitor report said the number of bomb attacks against US-backed forces and American troops in Syria has risen more than five-fold since the establishment of an Iran-backed force in June.
The recorded IED attacks predominantly took the form of roadside IEDs targeting SDF and US patrols, the consultancy said.
In the three months prior to June, there were 12 improvised explosive device attacks recorded, compared to the 78 in the three months following the creation of the Sunni tribal resistance movement.
“The recorded increase in attacks is most likely the result of a structured campaign by the tribal resistance movement,” said Columb Strack, principal Middle East analyst at IHS Markit.
“The increased number of attacks, and the locations in which attacks were conducted, appears to indicate concerted, organized efforts by these groups to pressure the US into withdrawing from Syria.”
The movement was formed "against foreign intervention and the American presence on Syrian soil," it said.