Homeland Security Secretary Janet Napolitano says there is no indication that the man who attempted to destroy an airliner in Detroit on Christmas Day is part of a larger terrorist plot.
Napolitano refused to say whether Umar Farouk Abdulmutallab has a connection to al-Qaida, citing the ongoing criminal investigation.
She confirmed that there was no air marshal on the plane with Abdulmutallab. They are not on every flight.
Napolitano says that despite Abdulmutallab's success at getting dangerous chemicals on board the plane, commercial flying is safe.
She says the United States is reviewing what security measures were used in Amsterdam, where he boarded the flight.
Napolitano appeared Sunday on CNN's "State of the Union."