Obama's former DHS secretary sounds alarm on Iranian sleeper cells, calls it concern of 'highest magnitude'

Ex-DHS chief warns of Iranian sleeper cells after U.S. strikes. ICE arrests undocumented Iranians as officials urge vigilance amid rising terror threats.

Madison is a production assistant for Fox News Digital on the Flash team.

"The presence in this country of undocumented migrants or Iranian nationals who have links to Hezbollah, IRGC, is, in my judgment, a domestic law enforcement concern of the highest magnitude," said former DHS Secretary Jeh Johnson during an interview on "Fox & Friends," Wednesday.