A Twitter account run by an Qaeda member said the Leader of the al Qaeda-linked Khorasan group was Killed in a U.S. air Strike in Syria, SITE monitoring service said on Sunday, following several days of uncertainty over whether he survived the raid. A U.S. official on Sept. 24 said the United States believed Mohsin al-Fadhli, a senior al Qaeda operative, had been Killed in a Strike a day earlier, but the Pentagon said several hours later that it was still investigating what had happened to him.