U.S. aircraft have concluded a third round of strikes against an al Qaeda cell inside Syria , two U.S. officials with direct knowledge of the just-completed mission told CNN on Thursday . The officials said it was a small number of strikes and that the targets included at least one top operative of what 's known as the Khorasan Group . The sources would not say who was targeted . They said it is too early to have an assessment of the strikes ' results . Khorasan is a group of hard-core al Qaeda operatives , many of whom moved to Syria from Pakistan in the last few years . The U.S. government has expressed concern about the group 's ability to make bombs that can get past security screening in airports and elsewhere . It targeted the Khorasan Group with a series of strikes in Syria in September . Those attacks came amid intelligence that suggested the group was plotting against a target in the U.S. homeland , as well as other Western targets , a senior U.S. official told CNN at the time . The group has `` suffered '' setbacks as a result of the strikes , which have killed a number of fighters and forced it to spread out , one law enforcement official who has seen the intelligence assessments said Thursday . Another U.S. official said `` some have been killed . They 're being hunted down and they have to think about what they do and that 's disruptive . '' At the same time , some of the Khorasan leadership is still believed to be alive and the group continues to pose a threat , according to the officials , who say some are still in Syria , actively plotting against the United States .
Strikes target what 's known as the Khorasan Group , officials say . It is too early to have an assessment of the results . Comment: