Terrorist plots against the United States and Europe may still be in the works despite this week's airstrikes against the al-Qaida cell known as Khorasan. FBI Director James Comey told reporters in Washington Thursday he is "not confident at all" that attacks by U.S.-led coalition disrupted Khorasan's plans.
Comey said the Khorasan group remains at the top of the FBI's list of terrorism concerns. It's comprised of al-Qaida veterans from Afghanistan and Pakistan, according to Comey. U.S. intelligence officials say Khorasan has been trying to perfect a non-metallic bomb that can evade airport security.
The director of the U.S. Federal Bureau of Investigation also said the U.S. believes it has identified an executioner from the Islamic State group - the man shrouded in black who spoke with a British accent in videos the terror group circulated showing the recent beheadings of two American journalists and a British aid worker.
Comey did not disclose the man's name or say whether he carried out the killings himself. British officials have previously said they were close to identifying the masked man.
About a dozen Americans are believed to be in Syria now fighting with extremist groups, Comey said, adding that more than 100 Americans have either been intercepted and arrested while trying to reach Syria, or have returned to the U.S. after joining the Syrian conflict.
The FBI chief said those who have come back to the U.S. after fighting with extremist groups are either under investigation, under surveilance or have been arrested.
Despite intensive attempts to identify and track Islamic State fighters active in the United States, Comey said he fears that a "home-grown" terror attack within the United States could be attempted by Islamic State supporters.