BEIRUT (Reuters) - U.S.-backed fighters in Syria have captured a senior Islamic State leader who served as an assistant to the group's self-declared "caliph" Abu Bakr al-Baghdadi, they said on Friday.
The Syrian Democratic Forces (SDF), a Kurdish-led militia alliance that holds the quarter of Syria east of the Euphrates, detained Osama al-Awaid last week, it said in a statement.
SDF fighters have been attempting to take Islamic State's last Syrian pocket of territory on the banks of the Euphrates near Iraq for weeks, in an offensive backed by U.S.-led air strikes.
They captured Awaid in a special operation in a village in eastern Syria, the statement said, adding that he had been a senior security official for Islamic State in the country.
More than a year after Islamic State's physical "caliphate" collapsed in both Syria and Iraq under military attack, Baghdadi's whereabouts remains a mystery.
However, despite its loss of territory, the group has been able to launch guerrilla attacks in areas controlled by both the Syrian and Iraqi governments.
(Reporting by Rodi Said and Angus McDowall)