Iraqi forces in co-ordination with U.S.-backed Syrian forces have captured five senior leaders of the Islamic State in Iraq and Syria group, the U.S.-led coalition said Thursday in a statement.
A Pentagon spokesperson, Marine Maj. Adrian J.T. Rankine-Galloway, said the U.S. credited Iraqi security forces with the militants' capture "on the Iraq-Syria border."
"These arrests are a significant blow to ISIS, as we continue to remove its leadership and fighters from the battlefield," Rankine-Galloway said.
ISIS fighters no longer control significant pockets of territory inside Iraq, but do maintain a grip inside Syria along Iraq's border.
The U.S.-led coalition supported Iraqi ground forces and Syrian fighters known as the Syrian Democratic Forces in the more than three-year war against ISIS.
After Iraqi forces retook the Iraqi city of Mosul from ISIS last summer, Syrian forces on the other side of the border claimed a series of swift victories, but the campaign stalled recently when Turkey launched a cross-border raid into Syria's north.
Earlier this month, the coalition announced a drive to clear the final pockets of ISIS territory inside Syria.
U.S. President Donald Trump tweeted about the anti-ISIS raid Thursday, saying those arrested were the "five most wanted" ISIS "leaders." It was unclear what criteria, if any, Trump was using to describe the ISIS operatives as the "five most wanted."
A U.S. national security official said there were no indications that the operation had captured Abu Bakr al-Baghdadi, the leader of ISIS who has long been the coalition's top target. The official wasn't authorized to discuss the targets publicly and requested anonymity.
Last year, the Pentagon said that there were "some indicators" that al-Baghdadi was still alive a month after Russia claimed to have killed him in a strike near the Syrian city of Raqqa.
None of the statements released Thursday from the president or the coalition named the ISIS fighters arrested.
The militant group swept into Iraq in the summer of 2014, taking control of nearly a third of the country. At the height of the group's power their self-proclaimed caliphate stretched from the edges of Aleppo in Syria to just north of the Iraqi capital, Baghdad.
With the group's physical caliphate now largely destroyed, anti-ISIS operations are increasingly focused on targeting the militants' remaining leadership.