Rami Abdel Rahman, head of the Britain-based Syrian Observatory for Human Rights war monitor, disputed the claim The SDF, an alliance of Kurdish and Arab fighters, is seeking to expel Daesh from a pocket of land in the Deir Ezzor BEIRUT: US-backed forces said Friday they had captured a leader of Daesh in eastern Syria where the Kurdish-led fighters have been battling the extremists. A statement by the Syrian Democratic Forces (SDF) identified the suspect as Osama Oweid Saleh and described him as “one of the most dangerous terrorists of the Daesh group.” But Rami Abdel Rahman, head of the Britain-based Syrian Observatory for Human Rights war monitor, disputed the claim. Abdel Rahman said Saleh was merely “a former local security official” in the eastern Deir Ezzor province. In its statement the SDF said that Saleh “was a security official for the terrorists in Deir Ezzor and took an active part in planning and implementing more than 40 terrorist operations” for the extremist group. It also said that he was “a security official” in other parts of Syria for Daesh, including in the former extremist bastion of Raqqa. Saleh, it said, was ambushed by SDF fighters and captured on November 22 in the Deir Ezzor countryside. Abdel Rahman told AFP that Saleh “could be a member of an Daesh sleeper cell.” The SDF, an alliance of Kurdish and Arab fighters, is seeking to expel Daesh from a pocket of land in the Deir Ezzor province near the Iraq border. The Kurdish-led forces have spearheaded the US-backed fight against Daesh in Syria. On Monday the Observatory reported that the SDF suffered record fatalities in an assault by Daesh as holdout extremists kept up a fierce defense of their last Syrian redoubt. It said a total of more than 200 people have been killed since around 500 Daesh fighters burst out of the fog shrouding the area in eastern Syria near the border with Iraq to launch their deadly assault last Friday. Ninety-two of the dead were SDF fighters while at least 61 extremists and 51 civilians, mostly their relatives, also died in the violence, it said.